Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

High quality-factor whispering-gallery mode in the photonic crystal hexagonal disk cavity

Han-Youl Ryu, Masaya Notomi, Guk-Hyun Kim, and Yong-Hee Lee

Open Access Open Access

Abstract

We study whispering-gallery-like modes in photonic crystal air-bridge slab micro-cavities having H2 defects using finite-difference time-domain calculations. The defect geometry is optimized to increase the quality factor (Q) of the H2-cavity whispering-gallery mode (WGM). By symmetrically distributing 12 nearest neighbor holes around the defect and controlling size of holes, it is possible to drastically increase the Q of >105 while preserving effective mode volume of the order of the cubic wavelength in material. In addition, we investigate the effect of a dielectric circular post located around the center of the H2 cavity. This post can act as current and heat flow paths that promise electrically-pumped thermally-stable lasing operation. It is interesting to observe that the introduction of the post structure increases the Q of the WGM upto 4×105 and the high Q >105 is still maintained even with large post size. Although diffractive out-coupling through the post is increased, radiated power outside the post is suppressed, which leads to large enhancement of the Q of the H2-cavity WGM.

©2004 Optical Society of America

Full Article  |  PDF Article
More Like This
Photonic crystal circular-shaped microcavity and its uniform cavity-waveguide coupling property due to presence of whispering gallery mode

Po-Tsung Lee, Tsan-Wen Lu, Chia-Ming Yu, and Chung-Chuan Tseng
Opt. Express 15(15) 9450-9457 (2007)

Two physical mechanisms for boosting the quality factor to cavity volume ratio of photonic crystal microcavities

Ph. Lalanne, S. Mias, and J. P. Hugonin
Opt. Express 12(3) 458-467 (2004)

High quality factors and room-temperature lasing in a modified single-defect photonic crystal cavity

Marko Lonc̆ar, Michael Hochberg, Axel Scherer, and Yueming Qiu
Opt. Lett. 29(7) 721-723 (2004)

View More...

Supplementary Material (6)

Media 1: GIF (332 KB)     
Media 2: GIF (89 KB)     
Media 3: GIF (370 KB)     
Media 4: GIF (336 KB)     
Media 5: GIF (309 KB)     
Media 6: GIF (295 KB)     

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 (13)
Fig. 1.
Fig. 1. Whispering-gallery mode (WGM) in photonic crystal hexagonal disk cavities. (a) H2-cavity WGM, (b) H3-cavity WGM, (c) H4-cavity WGM.

Download Full Size | PDF

Fig. 2.
Fig. 2. Quality factor (Q) of the WGM for H2, H3, and H4 disk cavities versus radius of air holes.

Download Full Size | PDF

Fig. 3.
Fig. 3. (a) Fourier-space electric field intensity distribution. Black circle represents light line. (b) Side-view electric field intensity of the WGM in Fig. 1(a). A color map of relative intensity scale is shown at the right of (b).

Download Full Size | PDF

Fig. 4.
Fig. 4. (a) Configuration of the modified H2 cavity. Here, nearest neighbor holes along the Γ-M direction are pushed away along the radial direction by the displacement parameter, p. (b) Quality factor as a function of p when radius of holes is 0.3 a. The blue dotted line indicates the position where nearest neighbor holes are symmetrically distributed.

Download Full Size | PDF

Fig. 5.
Fig. 5. Electric field intensity (|E|2) distribution of the WGM in a structure shown in Fig. 4(a).. A color map of relative intensity scale is shown at the bottom of figures. (a) |E|2 at the center plane of the slab. Circles represent air holes (b) Side view of the |E|2, (c) Fourier space representation. The black circle near center indicates light line.

Download Full Size | PDF

Fig. 6.
Fig. 6. (a) Configuration of the modified H2 cavity from the structure in Fig. 4(a) with p=(2-√3) a. Here, radius of nearest neighbor holes is modified from r to rm . (b) Quality factor as a function of rm for three r values.

Download Full Size | PDF

Fig. 7.
Fig. 7. (a) Quality factors as a function of rm for three r values in the structure, Fig. 6(a). (b) Effective mode volume of the WGM as a function of rm when radius of holes is 0.3 a.

Download Full Size | PDF

Fig. 8.
Fig. 8. (a) (330kB) Movie of electric field intensity of the modified H2-cavity WGM (b) (90kB) Movie of magnetic field amplitude of the modified H2-cavity WGM. Regular hole radius and modified hole radius are 0.3 a and 0.225 a, respectively. Black circles represent air holes.

Download Full Size | PDF

Fig. 9.
Fig. 9. Side -view of dielectric post structures. dP means post diameter. Here, dP is about 1.0 a. (a) Symmetric slab, (b) Asymmetric slab.

Download Full Size | PDF

Fig. 10.
Fig. 10. Quality factors of the WGM with the symmetric post plotted as a function of post diameter. Regular hole radius and modified hole radius are 0.3 a and 0.225 a, respectively.

Download Full Size | PDF

Fig. 11.
Fig. 11. (a) (340kB) Movie of the Poynting vector calculated at z=2.3 a when there is no post. (b) (270kB) Movie of the Poynting vector when the post diameter is 1.0 a. A dotted circle near the center indicates the post.

Download Full Size | PDF

Fig. 12.
Fig. 12. (a) Quality factor of the WGM with asymmetric posts versus post diameter. (b) Quality factor decomposed into the top and the bottom components. Each represents optical loss into the top air region and the bottom post region, respectively.

Download Full Size | PDF

Fig. 13.
Fig. 13. (a) (300kB) Movie of the Poynting vector calculated at z=2.3 a where there is no post. (b) (310kB) Movie of the Poynting vector calculated at z=-2.3 a where there is a post with diameter of 1.0 a. A dotted circle near the center indicates the post.

Download Full Size | PDF

Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use