Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Colorizing pure copper surface by ultrafast laser-induced near-subwavelength ripples

Open Access Open Access

Abstract

We demonstrate that the colorizing effect of angle dependence can be efficiently and conveniently achieved on the rippled surface of pure copper processed by the femtosecond laser with an out-of-focus method, which greatly improves the machining speed. Such a laser-induced colorization can occur in a wide range of laser fluence, which determines the coverage and morphological characteristics of laser-induced ripples and thus can finely tune the colorizing effect. By inspecting the colors and corresponding spectra of treated areas at different angles, the relationship between the diffracted light central wavelength and the laser-induced near-subwavelength grating is analyzed quantitatively based on the fundamental grating equation with the experimental grating parameters. The spectrum analysis indicates that for the laser fluence increasing in a suitable range, the more clarity and regularity of formed ripples should bring out a more prominent grating effect, which becomes further matching of the grating equation in a larger inspecting angle for the elimination of the influence of the diffused reflection light. In short, the study confirms that the colorizing phenomenon mainly ascribes to the grating diffraction effect of the laser-induced periodic surface ripples, which would help to enable the flexible control of the colorizing effect induced by laser processing on pure copper.

© 2014 Optical Society of America

1. Introduction

Surface micro/nano processing with femtosecond lasers has attracted much attention during these years, because a variety of micro/nano structures can be easily and efficiently induced on material surfaces after the femtosecond laser irradiation [16], which serves as a convenient physical way for greatly altering the physical characteristics of the materials. Above all, such ultrafast laser micro/nano structuring may change the optical properties of the processed surface obviously, such as the reflectance and the color [714]. Vorobyev and Guo used the femtosecond laser processing to change the silvery-white surface of Al into golden, grey and black [8]. Actually, the colorizing of aluminum that exhibited different color at different viewing angles, could also be obtained via laser-induced nanostructure-covered gratings [8]. Dusser et al. transferred a color picture onto a stainless steel surface by controlling the orientation of femtosecond laser-induced gratings [11]. Ahsan et al. colorized the stainless steel surface via femtosecond laser-induced micro/nano-gratings and periodic microholes [12]. Zhang et al. colorized silicon surface with regular nanohole arrays induced by femtosecond laser pulses [14].

In terms of application, this colorizing method is promising in label marking for the non-contacting machining process without pigment, which is clean and green. On the other hand, theoretically, it is important to investigate the relationship between the colorizing and the surface nano/micro structuring, which is the key to understand the laser colorizing phenomenon. On the whole, intuitively, it can be seen that the colorizing should ascribe to two different reasons: 1) the color effect of laser-induced surface nanostructures for metals [8], for instance the laser-induced nanoparticles that often turn out to be provided with different colors for different nanoscale sizes or structural characteristics; 2) the grating diffraction effect of laser-induced periodic surface structures [814] for all solid materials that tend to appear in the irradiation condition of moderate laser fluence, such as the periodic surface ripples (gratings) induced by the linearly-polarized laser. In particular, with regard to the colorizing cases relying on the viewing angle, it is obvious that this should be a phenomenon closely related to the latter kind of reason, that is, the grating diffraction effect. In recent years, some experimental results concerning the relationship between the color and the viewing angle have been presented in [11,13], which give the evidence of the grating diffraction effect originating the angle-dependence colorizing. As indicated by the contributed results of [11], the further quantitative confirmation of the grating diffraction equation based on the actual experimental data of the grating period, the viewing angle, and the spectrum peak of the colors should be feasible and meaningful: such a quantitatively experimental study would give insights on the critical factors that affect the colorizing phenomena, provide guidelines for improving the controllability of the colorizing effect, and thus be of importance for the application prospect of the technique.

In this paper, we report on the femtosecond laser-induced near-subwavelength ripples on the pure copper surface by an out-of-focus method and focus on the phenomenon of the color changing of the rippled surface. Via measuring the diffractive spectra of the treated areas in different inspecting angles with the white light of vertical illumination, we try to probe into the mechanisms of the colorizing phenomenon quantitatively based on the fundamental grating equation in terms of the angle-dependence spectra and the grating morphological parameters. With the help of the detailed spectrum analysis, we demonstrate the colorization on the surface of pure copper processed by femtosecond laser should mainly ascribe to the grating diffraction effect of the laser-induced periodic surface ripples. This investigation provides a clear and quantitative proof of the grating diffraction origin for the angle-dependence colorizing phenomenon occurring in ultrafast laser processing, which would help to give a guide for the flexible control of the colorizing effect.

2. Experiment

In the ultrafast laser processing experiment, a pure copper sample (JIS C1100, Mitsubishi Shindoh Co. Ltd, Cu ≧ 99.95%, fine-grained polycrystalline, surface roughness Ra = 0.2 μm, thickness = 2 mm) with a size of 4.0cm × 4.0cm was irradiated by a femtosecond laser (Coherent, Legend Elite USP HE + ) in the atmospheric environment with room temperature, as the experiment setup shown in Fig. 1(a). The central wavelength, the repetitive rate, and the pulse duration of the laser were 800 nm, 1 kHz, and 35 fs, respectively. A shutter was applied to control the propagation of the laser beam. Two neutral density filters were set in the light path to adjust the pulse energy that measured by a power meter (Coherent, FieldMax II). After the filters, the laser beam was vertically focused on the sample by a convex lens with a focal length of 200 mm. The sample was mounted on a 3D translation platform that was controlled by a computer. The machining process was monitored in real time by a CCD camera equipped with an objective lens of long focus.

 figure: Fig. 1

Fig. 1 Experiment setups. (a) The setup for the out-of-focus laser processing technique. (b) The setup for the optical and spectral characterizations of the laser processing sample surface.

Download Full Size | PPT Slide | PDF

With regard to the laser processing technique, we used an out-of-focus ablation method in order to improve the machining speed and efficiency. In detail, at the beginning of the focusing process, the sample was adjusted to obtain a good focusing condition for the convex lens. After the exact focus was located, the sample was moved to 15 mm away from the focus against the laser propagating direction (note that 15 mm is a typical value for our laser processing conditions that can balance the following two opposite parameters: the average laser fluence is high enough to achieve the fluence requirement of the ablation, and the processing efficiency is as high as possible). Then a scanning method as discussed in [6] was adopted to fabricate a 13mm × 13mm square area on the surface of the material with the scanning speed of 2.5 mm/s, and the scanning interval of 0.12 mm. By the out-of-focus ablation method with the above-mentioned typical out-of-focus distance, the machining efficiency can be improved greatly, because of the enormous increase of the effective irradiation area of the focused beam from the good focus condition to the significant out-of-focus condition. In detail, for the Gaussian laser beam with a diameter of 6 mm adopted in our experiment, focused by the lens with a focal length of 200 mm, the diameter (evaluated by the 1/e2 width of the light intensity envelope) in the focal plane is about 34 μm; in comparison, in the plane 15 mm away from the focus, the diameter of the irradiated area is about 450 μm. In view of such a large effective irradiated area, the interval of the adjacent scanning lines in our experiment can be set to an appropriate value of 120 μm, much larger than that in [6]. In addition, the scanning speed can also be raised vastly in the out-of-focus case. As a result, the machining efficiency can be improved greatly. Fitting for the above mentioned out-of-focus parameters, a pulse energy range from 300 μJ to 1100 μJ is used in the laser processing, which corresponds to a peak energy fluence of 0.38 J/cm2 to 1.38 J/cm2.

After the laser processing, the morphological characteristics of the treated area was firstly investigated with a scanning electron microscope (SEM, FEI, Quanta 400 FEG). Moreover, the optical and spectral characteristics were analyzed based on the experimental setup shown in Fig. 1(b). A white light source with continuum spectrum in the visible spectral range guided and output by a fiber bunch was transformed to a parallel beam with a large diameter by two lenses and an aperture. Then another aperture was used to control the diameter of the beam in order to coincide with the size of the processing area, and the beam vertically illuminated the processing area. Finally, in order to inspect the colorizing effect of the treated area, a camera (Canon, S5) was employed to take pictures from different angles in the same horizontal plane. Furthermore, for the quantitative characterization of the observed colors, the spectra of the scattered light in the same angles as the camera were also measured by a fiber optic spectrometer (Ocean Optics, HR4000).

3. Results and discussion

3.1 Laser-induced near-subwavelength ripples

The SEM images of the treated areas are shown in Fig. 2. Above all, the laser-induced near-subwavelength ripples [1517] are easily observed on the surface irradiated with the peak fluences varying from 0.38 J/cm2 to 1.38 J/cm2 in our experiment. Actually, in view of the good regularity of the ripples for the case of 1.38 J/cm2, it can be expected that the laser-induced ripples would also appear for the peak fluences higher than 1.38 J/cm2 in a certain range. That is, for the out-of-focus processing method, the laser-induced ripples can be achieved in a wide laser fluence range. In addition, it should be noted that the coverage of the laser-induced ripples on the surface increases along with the rising of the laser fluence. In the 0.38 J/cm2 case, the ripples are sparely formed on the surface left the most of the surface raw, and therefore, the coverage of ripples on the surface is quite low. In the 0.75 J/cm2 case, the ripples cover the majority of the treated area, only left the narrow region between the scanning lines without the complete cover of the ripples. In the 1.13 J/cm2 case, the ripples cover almost the entire treated area. Apparently, such a difference in the ripple coverage of the treated surface is caused by the different laser fluence and the Gaussian field distribution of the laser beam: in the laser irradiated surface, the induced near-subwavelength ripples tend to be produced in the regions with the laser fluence higher than the ablation threshold to some extent [18]. Therefore, along with the increase of the laser fluence, the markedly-rippled region will gradually extend from the central part of the scanning line to the peripheral part of the scanning line, which is determined by the field strength envelope of the Gaussian laser beam. Actually, for the above experimental results, the different rates of the ripple coverage can serve as a clue for us to study the effect of the ripples on the laser surface colorizing.

 figure: Fig. 2

Fig. 2 SEM images of the treated areas of pure copper. Group (a), (b), (c) are the areas irradiated by the laser pulses with the peak fluences of 0.38, 0.75, and 1.13 J/cm2, respectively. The images in Column (1) show the treated regions at the center of the scanning line, for which the magnified surface morphologies are shown in Column (2) and Column (3). The images in Column (4) show the treated regions between two adjacent scanning lines. In addition, the E-field direction of the polarized laser is indicated by a double arrow in the upper right corner of (a4).

Download Full Size | PPT Slide | PDF

Furthermore, the Fast Fourier Transformation (FFT) method was adopted to analyze the periods of the ripples appearing on the treated areas, as the accumulation results shown in Fig. 3(a) for the peak fluences of 0.38, 0.75, and 1.13 J/cm2. Obviously, as the laser fluence increases, the peak of the FFT curve becomes more prominent, meaning a great development of the laser-induced periodic surface structures as well as an increase of the regularity of the structures. Furthermore, the spacial frequency of the peak increases with the laser fluence increasing, which displays a decreasing trend of the ripple period (note that the spatial frequency and the ripple period have a simple reciprocal relationship: for instance, the peak frequency of 1.50 μm−1 in the case of 0.38 J/cm2 corresponds to a ripple period of 667 nm). Via fitting the frequency peaks, the corresponding periods are obtained as shown in Fig. 3(b). From the period curve, it can be clearly seen that the period of the ripples decreases with the laser fluence increasing until the peak fluence reaching 1.13 J/cm2. The periods of the ripples for the cases of 1.13, 1.26, and 1.38 J/cm2 are similar, which exhibits a saturation trend for the period decreasing phenomenon. As a matter of fact, for the laser-induced near-subwavelengh ripples, such a decreasing and saturation trend related to the laser fluence increasing is similar to that related to the pulse number increasing demonstrated in [15]. It means that there should be a similar reason for the period varying trend in respect to the two cases. That is, the incubation and growth process for the laser-induced ripples is longer and more fully with these laser parameters increasing. In detail, as described above, in regard to the Gaussian laser beam only the central part of the laser irradiated area with fluence higher than the ablation threshold can be significantly ablated. Therefore, the effective ablated area will increase as the laser fluence increases. Further considering the scanning technique, the rising of the effective ablated area of a single laser pulse will lead to the increasing of the effective pulse number for a specific location of the whole treated area, which means a stronger incubation effect for the laser-induced ripples. As estimated from the SEM images and calculated through the energy distribution of the Gaussian pulse, the diameters of the effective ablated areas are 40, 268 and 336 μm for the peak fluences of 0.38, 0.75, and 1.13 J/cm2, respectively. The corresponding effective pulse numbers for the spot in the center of the scanning line could be 16, 107 and 134 for the peak fluences of 0.38, 0.75, and 1.13 J/cm2, respectively. In view of the mechanisms responsible for the laser-induced near-subwavelength ripples [1517], it is clear that such a decreasing trend of the ripple period is consistent with the prediction of the grating-assisted SP-laser coupling theory [15]. For the peak fluence higher than 1.13 J/cm2, the cease of such a decreasing trend appears, which reveals that the grating-assisted SP-laser coupling achieves a balance for certain reasons, such as the stop of the groove deepening due to the stronger thermal effect of the laser pulse with higher fluence. On the whole, besides the above-mentioned varying coverage of the ripples on the treated areas, the varying period of the ripples for different laser fluences can provide us another clue for quantitatively exploring the effect of the ripples on the laser surface colorizing.

 figure: Fig. 3

Fig. 3 FFT results of the SEM images. (a) Accumulated results of the FFT matrix for the cases of 0.38, 0.75 and 1.13 J/cm2, respectively. (b) The corresponding periods derived from the peaks of the accumulated results as a function of peak fluence.

Download Full Size | PPT Slide | PDF

3.2 Color and spectrum

After the laser processing, a multicolored appearance arises on the treated surface, for which the presented color changes in terms of the inspecting angle and the laser processing condition. As shown in Fig. 4(a), concerning the vivid color appearing on the nine square treated areas, the upper right square is in yellow, while the other squares evolve into green, blue, and purple gradually. In detail, with regard to the three horizontal rows, there appears a prominent blue shift from top to bottom due to the change of the inspecting angle. Meanwhile, for the three squares of a certain row, the color is also changing, which may originate in the varying of the surface morphologies, in particular the grating period, on account of the different employed laser fluences corresponding to the areas. In addition, in Fig. 4(b) for a specific treated area illuminated by the parallel white light of normal incidence, the grating rainbow projecting onto a white paper can be clearly observed.

 figure: Fig. 4

Fig. 4 The color features of the treated copper surface. (a) The multicolored appearance of the treated surface was taken by a camera with the illumination of a white light. Irradiated fluences: 1.38 J/cm2 (up), 1.26 J/cm2 (middle), and 1.13 J/cm2 (down) in the left column; 1.00 J/cm2 (up), 0.88 J/cm2 (middle), and 0.75 J/cm2 (down) in the middle column; 0.63J/cm2 (up), 0.50 J/cm2 (middle), and 0.38 J/cm2 (down) in the right column. (b) The grating rainbow projects onto a white paper when the treated square area corresponding to the peak fluence of 1.13 J/cm2 is illuminated by the parallel white light of normal incidence. (c) The color evolution of the treated areas is presented as functions of the laser fluence and the inspecting angle (θ) under the illumination of parallel white light of normal incident, as shown in Fig. 1(b).

Download Full Size | PPT Slide | PDF

Moreover, the images taken by the experimental setup of Fig. 1(b) are shown in Fig. 4(c), which demonstrate the relationship between the colors of the treated square areas and the inspecting angle and the laser fluence. Above all, the results evidently indicate that in different inspecting angles, the treated areas illuminated by the same white light of normal incidence appear in different colors. Obviously, as the inspecting angle increases, a red shift of the present color can be clearly observed. It is a distinct evidence of the grating diffraction effect associated with the laser-induced ripples. However, for the cases with the same inspecting angle but different laser fluences, although there are also some color changes owing to the varying of the ripple period, it is not easy to directly trace the changing trend of theses colors from the optical images because of the low color contrast, in particular for the case of small inspecting angles. That is, in order to quantify the color change in terms of the inspecting angle and the grating period, more in-depth spectroscopic studies of the appearing colors is required. Therefore, for quantitatively analyzing the observed color in a specific inspecting angle, we also measured the corresponding spectrum of the scattered light in the angle, which would provide the underlying relationship among the scattering spectrum peak, the inspecting angle, and the grating period determined by the laser fluence. On the other hand, as described above, the angle-dependence shift of the appearing colors of the treated areas strongly implies the grating diffraction origin for the observed phenomenon. In consequence, we try to use the grating diffraction theory to verify the issue. Theoretically, for a grating illuminated by a normal incident white-light beam, the central wavelength of the diffracted light in a certain angle follows a simple formula:

dsinθ=mλ
where λ is the central wavelength, d is the period of the grating, θ is the inspecting angle, and m is the diffraction order. Note that for the laser-induced subwavelength ripples with the periods smaller than the laser wavelength of 800 nm, m should not be larger than 1 for the visible spectral range concerned in the study. Thus, based on the formula with the data of d obtained from FFT analyses of SEM images and θ used in the experiments, we can compare the experimental spectrum peaks with the theoretical diffracted wavelength of a grating quantitatively to evaluate the effect of the grating diffraction on the colorizing phenomenon.

With the help of the experimental set-up of Fig. 1(b) for the spectrum acquisition, the spectral information of diffracted light from the square treated area can be readily obtained. For example, concerning the effect of the ripple period, in the inspecting angle of 50 degrees the measured spectra of the diffracted light for the treated areas corresponding to three different peak fluences are shown in Fig. 5(a), which have been first normalized with the measured spectrum of the incident white light, and then normalized to make the most prominent peak equal to 1, in order to eliminate the influence of the spectrum distribution and characteristic of the incident white light. For the spectra, the peak features are obvious for the cases of 0.75 J/cm2 and 1.13 J/cm2; whereas, the spectrum for the case of 0.38 J/cm2 was similar to that for the non-treated surface. The results indicate that as the peak fluence increases, the grating diffraction effect becomes more pronounced, which is consistent with the surface morphological observation of Fig. 2. For the low coverage of ripples in the case of 0.38 J/cm2, the diffuse scattering light from the surface with a certain roughness is the majority of the received light in a specific inspecting direction, which makes the spectrum close to that of the non-treated surface. With the increasing of the peak fluence, the increasing coverage of the ripples on the treated areas brings about the prevalence of the grating effect, and thus the grating diffraction light becomes the important part of the spectrum that exhibits a blue shift for the decreasing of the grating period as the peak fluence increases. However, it should be noted that here the peak feature in the spectrum of 1.13 J/cm2 is weaker than that in the spectrum of 0.75 J/cm2, which seems abnormal. The issue leads us to think about more factors that would affect the spectral peak features.

 figure: Fig. 5

Fig. 5 Spectra of the diffracted light from the sample surface. (a) At the angle of 50 degrees, the diffracted spectra of the treated areas corresponding to the peak fluence of 0.38, 0.75 and 1.13 J/cm2, respectively, and the non-irradiated surface. Note that the diffracted spectra have been divided by the spectrum of the incident light and then normalized. In addition, for reference, the reflectivity of the pure copper sample measured by an integrating sphere has also been provided. (b) The diffracted spectra corresponding to the peak fluence of 0.38, 0.75 and 1.13 J/cm2 shown in (a) are further divided by the reflection spectrum of the pure copper sample and normalized. (c) In the inspecting angles of 40, 50, 60 and 70 degrees, the diffracted spectra of the treated area corresponding to the peak fluence of 0.75 J/cm2 are presented after the same spectral transformation like (b).

Download Full Size | PPT Slide | PDF

Actually, as shown by the solid curve in Fig. 5(a) measured by the fiber optic spectrometer equipped with an integrating sphere for the non-treated surface, the intrinsic reflectivity of the pure copper surface exhibits a strong spectral dependence in the visual range. It can be expected that such a strong wavelength dependence reflectivity of the non-treated surface would influence the spectral peak features of the diffracted light from the reflection grating, in particular for the spectral range of 550 to 650 nm. Therefore, for accurately describing the effect of the laser-induced grating of itself, we should further divide the diffraction spectrum by the intrinsic reflection spectrum of the pure copper, as shown by Fig. 5(b). After such a transformation, one can see that not only the peak feature of 1.13 J/cm2, but also that of 0.38 J/cm2, have been improved greatly: the peaks of the spectra for 0.38 J/cm2 and 1.13 J/cm2 become more prominent symmetrical. Along with the increasing of the laser fluence that gives rise to the more pronounced laser-induced grating, the derived diffraction peak becomes more significant. The result evidently shows the diffraction effect of the laser-induced grating.

In the other side, it can be noticed that the spectral width of the measured peaks are quite wide. For example, for the case of 0.75 J/cm2 in Fig. 5(b) the spectral width of the peak is 150 nm. In essence, it is caused by the relatively large range of ripple periodicities and the long-range irregular characteristic of the ripples, which can be understood easily by the FFT results of Fig. 3(a). In detail, for the case of 0.75 J/cm2 in Fig. 3(a), the FWHM range of the spatial frequency peak is from 1.5 μm−1 to 2.0 μm−1, which corresponds to the ripple period ranges from 500 μm to 667 μm. Such a wide period distribution would lead to a spectral width of 130 nm at the viewing anlge of 50 degrees, close to the measured one shown in Fig. 5.

With the same spectral transformation, for four different inspecting angles the measured spectra of the diffracted light for the treated area corresponding to the peak fluence of 0.75 J/cm2 are shown in Fig. 5(c), which clearly exhibits a red shift for the spectral peaks due to the increasing of the inspecting angle. It is also a definite evidence of the grating diffraction effect. Furthermore, in Fig. 6(a) for the four different inspecting angles, the central wavelengths of the spectral peaks are shown as a function of the laser fluence. For ease of comparison, along with the discrete experimental data, the theoretical wavelengths of the diffraction light are also demonstrated as different curves in Fig. 6(b) for the corresponding laser fluence cases, which are derived from the grating equation Eq. (1) on account of the ripple periods in Fig. 3(b) obtained from the SEM images. By comparing the experimental results and the theoretical results, we can get meaningful insights into the grating diffraction effect of the rippled surface. Above all, for a large inspecting angle, such as the case of 70 degrees, the experimental result is well consistent with the theoretical result, which definitely confirms the diffraction effect of the laser-induced gratings. However, as the inspecting angle decreases, such as the cases of 60 and 50 degrees, in the low laser fluecne range the deviation between the experimental results and the theoretical results becomes significant. As described above, for the low laser fluence cases the coverage of the laser-induced ripples is small, and thus the effect of the diffuse reflection light of the original surface become prominent, which influences the derived results greatly and makes the measurements depart from the predictions of the grating theory. In particular, towards the small inspecting angle, such as the case of 40 degrees, such a departure appears in the whole measured range of the laser fluence—the effect of the diffuse reflection light become more significant in the small inspecting angle for the vertical incidence of the illumination white light. On the whole, the results with the peak fluence larger than 0.75 J/cm2 indicate when the treated surface is well covered by laser-induced ripples with good regularity, the present color in a certain inspecting angle is determined by the diffraction effect of the laser-induced gratings.

 figure: Fig. 6

Fig. 6 The central wavelengths of the spectral peaks are presented as functions of (a) the peak fluence for the inspecting angles of 40, 50, 60 and 70 degrees and (b) the inspecting angle for the peak fluences of 0.38, 0.75 and 1.13 J/cm2.

Download Full Size | PPT Slide | PDF

As above experimental results show, the laser fluence that determines the coverage, the regularity, and the period of laser-induced ripples, is the key factor for the prevalence of the grating diffraction effect. In order to further confirm the conclusion, for four different laser fluences, we had also measured the spectra of the scattered light as a function of the inspecting angle in the range from 40 to 70 degrees with an angle interval of 2 degrees. The central wavelengths for the spectral peaks obtained after the above-mentioned spectrum transformation are shown in Fig. 6(b). From the theoretical curves derived from the grating equation Eq. (1) based on the grating period data of Fig. 3(b), one can clearly see that the experimental data of 1.13 J/cm2 and 1.38 J/cm2 matches the theoretical curves well in the whole measured range. The results further provide a quantitative proof of the grating diffraction mechanism for the colorizing effect of the laser processing surface on pure copper that is well rippled for the high enough laser fluence. In contrast, for the other two laser fluence cases, although there is a similar tendency for the curves, more significant deviation between the experimental data and the theoretical curve appears. Resembling the cases of low laser fluences discussed in Fig. 6(a), such a deviation should originate in the low coverage of laser-induced ripples on the treated surface in the cases of 0.38 J/cm2 and 0.75 J/cm2, which would make the measured light spectrum come from a mixture of the light diffracted by laser-induced gratings and the one scattered by the non-rippled surface. In detail, as shown in Fig. 5(a), the pure copper has a high reflectivity in the spectral range above 600 nm. Therefore, when the wavelength of the diffraction light is smaller than 600 nm, the diffuse reflection light from the non-rippled region should induce a red shift to the spectral peak of the mixed light, as the experimental results show. Moreover, as described above, due to the vertical incidence of the illumination light, the strength of the scattered light from the non-rippled region presents a decreasing trend as the inspecting angle increases. That is, the effect of the diffuse reflection light should weaken along with the increasing of the inspecting angle. In other word, the deviation between the experimental results and the theoretical results tends to decrease as the inspecting angle increases, which also agrees with the results shown in Fig. 6(b). Actually, for the cases with a high coverage of laser-induced ripples, such as the cases with the peak fluences of 1.13 J/cm2 and 1.38 J/cm2, the effect of the diffuse reflection light can be greatly reduced, and thus the measured spectrum is almost completely determined by the diffracted light based on the grating effect. On the other hand, besides the coverage of the ripples, the morphological characteristics of the ripples would also influence the effect of the colorizing. In short, as shown in the Figs. 2(a3), 2(b3) and 2(c3), along with the laser fluence increasing in our experimental range, the formed gratings become more clear and regular, which will bring out a more prominent grating effect. That is, a more sharp and vivid colorization effect may appear.

In short, with appropriate processing parameters, the grating diffraction effect can be dominant in the colorizing mechanisms of the laser-textured surface of pure copper. Therefore, such a clear and unique colorizing mechanism makes it possible to accurately control the presented color of the material in a specific viewing angle by the laser processing method, which depends mainly on the grating parameters, in particular the grating period, rather than the intrinsic optical properties of the formed materials on the treated surface, for example the individual optical properties of various micro/nano structures induced by the laser.

4. Conclusion

We demonstrate that the colorizing effect with angle dependence can be easily achieved on the rippled surface of pure copper processed by femtosecond laser with an out-of-focus method that can greatly accelerate the processing. Such a colorizing phenomenon can occur in a wide range of the laser fluence, which determines the coverage and the morphological characteristics of the laser-induced ripples and thus can finely tune the colorizing effect via the spontaneous changing of the induced ripple period. Furthermore, by measuring the scattering spectra of treated areas in different inspecting angles with the vertical incident white light, the mechanism of the colorizing phenomenon has been investigated quantitatively based on the fundamental grating equation with the experimental grating parameters. In terms of the detail spectrum analysis, we demonstrate that the colorizing phenomenon on the laser processing surface of pure copper mainly ascribes to the grating diffraction effect of the laser-induced periodic ripples. In detail, the spectrum analysis indicates that for the laser fluence increasing in a suitable range, the more clarity and regularity of the formed ripples should bring out a more prominent grating effect, which becomes more significant in a larger inspecting angle for the elimination of the influence of the diffuse reflection light. On the whole, the investigation can serve as a quantitative proof of the grating diffraction origin for the angle-dependence colorizing phenomenon occurring on laser processing surface. In addition, it would help to enable the flexible control of the colors induced by the femtosecond laser on pure copper.

Acknowledgments

The authors are grateful to Y. F. Liu and X. R. Zeng for their support in the experiments. This work was supported by the National Natural Science Foundation of China (11274400, 11004208, 10574165, 11274397, 91022012 and 20973203), the Government of Guangdong Province for NSF (8151027501 000010), the Open Fund of the State Key Laboratory of High Field Laser Physics (Shanghai Institute of Optics and Fine Mechanics), the Hundred Talents Program of Sun Yat-Sen University, and the Program for Changjiang Scholars and Innovative Research Team in University (IRT13042).

References and links

1. A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999). [CrossRef]  

2. A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003). [CrossRef]  

3. J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005). [CrossRef]  

4. J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005). [CrossRef]  

5. M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007). [CrossRef]  

6. M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008). [CrossRef]   [PubMed]  

7. A. Y. Vorobyev and C. Guo, “Femtosecond laser blackening of platinum,” J. Appl. Phys. 104(5), 053516 (2008). [CrossRef]  

8. A. Y. Vorobyev and C. Guo, “Colorizing metals with femtosecond laser pulses,” Appl. Phys. Lett. 92(4), 041914 (2008). [CrossRef]  

9. Y. Yang, J. Yang, C. Liang, and H. Wang, “Ultra-broadband enhanced absorption of metal surfaces structured by femtosecond laser pulses,” Opt. Express 16(15), 11259–11265 (2008). [CrossRef]   [PubMed]  

10. A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009). [CrossRef]   [PubMed]  

11. B. Dusser, Z. Sagan, H. Soder, N. Faure, J. P. Colombier, M. Jourlin, and E. Audouard, “Controlled nanostructrures formation by ultra fast laser pulses for color marking,” Opt. Express 18(3), 2913–2924 (2010). [CrossRef]   [PubMed]  

12. M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011). [CrossRef]  

13. J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012). [CrossRef]  

14. C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012). [CrossRef]   [PubMed]  

15. M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009). [CrossRef]   [PubMed]  

16. J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009). [CrossRef]  

17. F. Garrelie, J. P. Colombier, F. Pigeon, S. Tonchev, N. Faure, M. Bounhalli, S. Reynaud, and O. Parriaux, “Evidence of surface plasmon resonance in ultrafast laser-induced ripples,” Opt. Express 19(10), 9035–9043 (2011). [CrossRef]   [PubMed]  

18. M. Huang and Z. Xu, “Spontaneous scaling down of femtosecond laser-induced apertures towards the 10-nanometer level: the excitation of quasistatic surface plasmons,” Laser Photon. Rev. early view (2014).

References

  • View by:

  1. A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
    [Crossref]
  2. A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003).
    [Crossref]
  3. J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
    [Crossref]
  4. J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005).
    [Crossref]
  5. M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
    [Crossref]
  6. M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
    [Crossref] [PubMed]
  7. A. Y. Vorobyev and C. Guo, “Femtosecond laser blackening of platinum,” J. Appl. Phys. 104(5), 053516 (2008).
    [Crossref]
  8. A. Y. Vorobyev and C. Guo, “Colorizing metals with femtosecond laser pulses,” Appl. Phys. Lett. 92(4), 041914 (2008).
    [Crossref]
  9. Y. Yang, J. Yang, C. Liang, and H. Wang, “Ultra-broadband enhanced absorption of metal surfaces structured by femtosecond laser pulses,” Opt. Express 16(15), 11259–11265 (2008).
    [Crossref] [PubMed]
  10. A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
    [Crossref] [PubMed]
  11. B. Dusser, Z. Sagan, H. Soder, N. Faure, J. P. Colombier, M. Jourlin, and E. Audouard, “Controlled nanostructrures formation by ultra fast laser pulses for color marking,” Opt. Express 18(3), 2913–2924 (2010).
    [Crossref] [PubMed]
  12. M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
    [Crossref]
  13. J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
    [Crossref]
  14. C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012).
    [Crossref] [PubMed]
  15. M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
    [Crossref] [PubMed]
  16. J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
    [Crossref]
  17. F. Garrelie, J. P. Colombier, F. Pigeon, S. Tonchev, N. Faure, M. Bounhalli, S. Reynaud, and O. Parriaux, “Evidence of surface plasmon resonance in ultrafast laser-induced ripples,” Opt. Express 19(10), 9035–9043 (2011).
    [Crossref] [PubMed]
  18. M. Huang and Z. Xu, “Spontaneous scaling down of femtosecond laser-induced apertures towards the 10-nanometer level: the excitation of quasistatic surface plasmons,” Laser Photon. Rev. early view (2014).

2012 (2)

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012).
[Crossref] [PubMed]

2011 (2)

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

F. Garrelie, J. P. Colombier, F. Pigeon, S. Tonchev, N. Faure, M. Bounhalli, S. Reynaud, and O. Parriaux, “Evidence of surface plasmon resonance in ultrafast laser-induced ripples,” Opt. Express 19(10), 9035–9043 (2011).
[Crossref] [PubMed]

2010 (1)

2009 (3)

A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
[Crossref]

2008 (4)

2007 (1)

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

2005 (2)

J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
[Crossref]

J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005).
[Crossref]

2003 (1)

A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003).
[Crossref]

1999 (1)

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Ahmed, F.

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

Ahsan, M. S.

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

Audouard, E.

B. Dusser, Z. Sagan, H. Soder, N. Faure, J. P. Colombier, M. Jourlin, and E. Audouard, “Controlled nanostructrures formation by ultra fast laser pulses for color marking,” Opt. Express 18(3), 2913–2924 (2010).
[Crossref] [PubMed]

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

Bonse, J.

J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
[Crossref]

J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
[Crossref]

Borowiec, A.

A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003).
[Crossref]

Bounhalli, M.

Brown, W. D.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Cheng, Y.

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
[Crossref] [PubMed]

Colombier, J. P.

Dai, Q.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Dai, Q. F.

Dusser, B.

Faure, N.

Garrelie, F.

F. Garrelie, J. P. Colombier, F. Pigeon, S. Tonchev, N. Faure, M. Bounhalli, S. Reynaud, and O. Parriaux, “Evidence of surface plasmon resonance in ultrafast laser-induced ripples,” Opt. Express 19(10), 9035–9043 (2011).
[Crossref] [PubMed]

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

Guillermin, M.

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

Guo, C.

A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
[Crossref] [PubMed]

A. Y. Vorobyev and C. Guo, “Femtosecond laser blackening of platinum,” J. Appl. Phys. 104(5), 053516 (2008).
[Crossref]

A. Y. Vorobyev and C. Guo, “Colorizing metals with femtosecond laser pulses,” Appl. Phys. Lett. 92(4), 041914 (2008).
[Crossref]

J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005).
[Crossref]

Haugen, H. K.

A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003).
[Crossref]

Huang, M.

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
[Crossref] [PubMed]

Jourlin, M.

Jun, M. B. G.

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

Kim, Y. G.

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

Krüger, J.

J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
[Crossref]

Lan, S.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012).
[Crossref] [PubMed]

Lee, M. S.

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

Liang, C.

Liu, H.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Liu, H. Y.

Lysak, T. M.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012).
[Crossref] [PubMed]

Makin, V. S.

A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
[Crossref] [PubMed]

Malshe, A. P.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Molian, P. A.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Munz, M.

J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
[Crossref]

Ozkan, A. M.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Parriaux, O.

Pigeon, F.

Railkar, T. A.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Reynaud, S.

Rosenfeld, A.

J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
[Crossref]

Sagan, Z.

Sanner, N.

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

Shirk, M. D.

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

Soder, H.

B. Dusser, Z. Sagan, H. Soder, N. Faure, J. P. Colombier, M. Jourlin, and E. Audouard, “Controlled nanostructrures formation by ultra fast laser pulses for color marking,” Opt. Express 18(3), 2913–2924 (2010).
[Crossref] [PubMed]

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

Sturm, H.

J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
[Crossref]

Tonchev, S.

Trofimov, V. A.

C. Y. Zhang, J. W. Yao, H. Y. Liu, Q. F. Dai, L. J. Wu, S. Lan, V. A. Trofimov, and T. M. Lysak, “Colorizing silicon surface with regular nanohole arrays induced by femtosecond laser pulses,” Opt. Lett. 37(6), 1106–1108 (2012).
[Crossref] [PubMed]

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Venu Gopal, A.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Vorobyev, A. Y.

A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
[Crossref] [PubMed]

A. Y. Vorobyev and C. Guo, “Femtosecond laser blackening of platinum,” J. Appl. Phys. 104(5), 053516 (2008).
[Crossref]

A. Y. Vorobyev and C. Guo, “Colorizing metals with femtosecond laser pulses,” Appl. Phys. Lett. 92(4), 041914 (2008).
[Crossref]

Wang, H.

Wang, J.

J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005).
[Crossref]

Wu, L.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Wu, L. J.

Xu, N.

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
[Crossref] [PubMed]

Xu, Z.

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
[Crossref] [PubMed]

Yang, J.

Yang, Y.

Yao, J.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Yao, J. W.

Zhang, C.

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

Zhang, C. Y.

Zhao, F.

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Large area uniform nanostructures fabricated by direct femtosecond laser ablation,” Opt. Express 16(23), 19354–19365 (2008).
[Crossref] [PubMed]

ACS Nano (1)

M. Huang, F. Zhao, Y. Cheng, N. Xu, and Z. Xu, “Origin of Laser-Induced Near-Subwavelength Ripples: Interference between Surface Plasmons and Incident Laser,” ACS Nano 3(12), 4062–4070 (2009).
[Crossref] [PubMed]

Appl. Phys. Lett. (4)

A. M. Ozkan, A. P. Malshe, T. A. Railkar, W. D. Brown, M. D. Shirk, and P. A. Molian, “Femtosecond laser-induced periodic structure writing on diamond crystals and microclusters,” Appl. Phys. Lett. 75(23), 3716–3718 (1999).
[Crossref]

A. Borowiec and H. K. Haugen, “Subwavelength ripple formation on the surfaces of compound semiconductors irradiated with femtosecond laser pulses,” Appl. Phys. Lett. 82(25), 4462–4464 (2003).
[Crossref]

J. Wang and C. Guo, “Ultrafast dynamics of femtosecond laser-induced periodic surface pattern formation on metals,” Appl. Phys. Lett. 87(25), 251914 (2005).
[Crossref]

A. Y. Vorobyev and C. Guo, “Colorizing metals with femtosecond laser pulses,” Appl. Phys. Lett. 92(4), 041914 (2008).
[Crossref]

Appl. Surf. Sci. (3)

M. Guillermin, F. Garrelie, N. Sanner, E. Audouard, and H. Soder, “Single- and multi-pulse formation of surface structures under static femtosecond irradiation,” Appl. Surf. Sci. 253(19), 8075–8079 (2007).
[Crossref]

M. S. Ahsan, F. Ahmed, Y. G. Kim, M. S. Lee, and M. B. G. Jun, “Colorizing stainless steel surface by femtosecond laser induced micro/nano-structures,” Appl. Surf. Sci. 257(17), 7771–7777 (2011).
[Crossref]

J. Yao, C. Zhang, H. Liu, Q. Dai, L. Wu, S. Lan, A. Venu Gopal, V. A. Trofimov, and T. M. Lysak, “Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses,” Appl. Surf. Sci. 258(19), 7625–7632 (2012).
[Crossref]

J. Appl. Phys. (3)

J. Bonse, A. Rosenfeld, and J. Krüger, “On the role of surface plasmon polaritons in the formation of laser-induced periodic surface structures upon irradiation of silicon by femtosecond-laser pulses,” J. Appl. Phys. 106(10), 104910 (2009).
[Crossref]

J. Bonse, M. Munz, and H. Sturm, “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses,” J. Appl. Phys. 97(1), 013538 (2005).
[Crossref]

A. Y. Vorobyev and C. Guo, “Femtosecond laser blackening of platinum,” J. Appl. Phys. 104(5), 053516 (2008).
[Crossref]

Opt. Express (4)

Opt. Lett. (1)

Phys. Rev. Lett. (1)

A. Y. Vorobyev, V. S. Makin, and C. Guo, “Brighter light sources from black metal: significant increase in emission efficiency of incandescent light sources,” Phys. Rev. Lett. 102(23), 234301 (2009).
[Crossref] [PubMed]

Other (1)

M. Huang and Z. Xu, “Spontaneous scaling down of femtosecond laser-induced apertures towards the 10-nanometer level: the excitation of quasistatic surface plasmons,” Laser Photon. Rev. early view (2014).

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1
Fig. 1 Experiment setups. (a) The setup for the out-of-focus laser processing technique. (b) The setup for the optical and spectral characterizations of the laser processing sample surface.
Fig. 2
Fig. 2 SEM images of the treated areas of pure copper. Group (a), (b), (c) are the areas irradiated by the laser pulses with the peak fluences of 0.38, 0.75, and 1.13 J/cm2, respectively. The images in Column (1) show the treated regions at the center of the scanning line, for which the magnified surface morphologies are shown in Column (2) and Column (3). The images in Column (4) show the treated regions between two adjacent scanning lines. In addition, the E-field direction of the polarized laser is indicated by a double arrow in the upper right corner of (a4).
Fig. 3
Fig. 3 FFT results of the SEM images. (a) Accumulated results of the FFT matrix for the cases of 0.38, 0.75 and 1.13 J/cm2, respectively. (b) The corresponding periods derived from the peaks of the accumulated results as a function of peak fluence.
Fig. 4
Fig. 4 The color features of the treated copper surface. (a) The multicolored appearance of the treated surface was taken by a camera with the illumination of a white light. Irradiated fluences: 1.38 J/cm2 (up), 1.26 J/cm2 (middle), and 1.13 J/cm2 (down) in the left column; 1.00 J/cm2 (up), 0.88 J/cm2 (middle), and 0.75 J/cm2 (down) in the middle column; 0.63J/cm2 (up), 0.50 J/cm2 (middle), and 0.38 J/cm2 (down) in the right column. (b) The grating rainbow projects onto a white paper when the treated square area corresponding to the peak fluence of 1.13 J/cm2 is illuminated by the parallel white light of normal incidence. (c) The color evolution of the treated areas is presented as functions of the laser fluence and the inspecting angle (θ) under the illumination of parallel white light of normal incident, as shown in Fig. 1(b).
Fig. 5
Fig. 5 Spectra of the diffracted light from the sample surface. (a) At the angle of 50 degrees, the diffracted spectra of the treated areas corresponding to the peak fluence of 0.38, 0.75 and 1.13 J/cm2, respectively, and the non-irradiated surface. Note that the diffracted spectra have been divided by the spectrum of the incident light and then normalized. In addition, for reference, the reflectivity of the pure copper sample measured by an integrating sphere has also been provided. (b) The diffracted spectra corresponding to the peak fluence of 0.38, 0.75 and 1.13 J/cm2 shown in (a) are further divided by the reflection spectrum of the pure copper sample and normalized. (c) In the inspecting angles of 40, 50, 60 and 70 degrees, the diffracted spectra of the treated area corresponding to the peak fluence of 0.75 J/cm2 are presented after the same spectral transformation like (b).
Fig. 6
Fig. 6 The central wavelengths of the spectral peaks are presented as functions of (a) the peak fluence for the inspecting angles of 40, 50, 60 and 70 degrees and (b) the inspecting angle for the peak fluences of 0.38, 0.75 and 1.13 J/cm2.

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

dsinθ=mλ

Metrics

Select as filters


Select Topics Cancel
© Copyright 2022 | Optica Publishing Group. All Rights Reserved