Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
  • 2013 Conference on Lasers and Electro-Optics - International Quantum Electronics Conference
  • (Optica Publishing Group, 2013),
  • paper CFIE_P_7

Efficient broadband 400 nm noncollinear second harmonic generation of chirped femtosecond laser pulses in BBO and LBO

Not Accessible

Your library or personal account may give you access

Abstract

Regarding the field of ultra-short pulses, frequency doubling has many attractive features like extending the wavelength range, improving the pulse contrast or obtaining even shorter pulses. However, fs second harmonic generation (SHG) faces specific difficulties mainly due to the phase-matching (PM) condition to be fulfilled on a very broad spectrum and to the high electric field associated. For short pulse durations, phase mismatch, whose first order approximation corresponds to group-velocity mismatch (GVM), leads to temporal broadening and reduces the conversion efficiency (CE). At high intensities, third order nonlinear phenomena (self-phase modulation, cross-phase modulation, self-focusing …) can decrease the CE and alter the SHG beam quality. In order to reduce these effects, one can use a thin crystal at moderate power density at the expense, however, of the CE. These problems have been extensively studied these last years and several solutions proposed. In particular, noncollinear (NC) geometries generally make it possible to suppress the GVM by adjusting incidence angles of fundamental pulses on a nonlinear crystal. It also has several other specific advantages such as the direct separation of the three interacting waves. Nevertheless, raw application of the NC geometry concept usually gives a very low CE due to poor spatial and temporal overlap. High energy, high efficiency fs SHG is thus far from trivial and still remains a scientific and technical challenge. Smith [1] and later Liu et al [2] have detailed an analysis of the three wave-mixing ultra-broadband PM condition using the concept of pulse-front tilt (PFT). We applied their model to design an original set-up for high power achromatic fs NC SHG with PFT in Beta-Barium Borate (BBO) and Lithium Triborate (LBO). The fundamental wave is delivered by a classical multipass CPA Ti:Sa system (carrier wavelength ~800nm, energy per pulse up to 100 mJ, 50 fs pulse duration, 20 Hz repetition rate, see [3] for more details). Two set-ups were designed in order to simultaneously match the pulse-fronts of the three waves as well as their GV. The first one uses prisms and is well-suited for moderate input fundamental power, whereas the second uses gratings at high input energy levels. For input fundamental energies in the mJ range, BBO and LBO gave similar results. The measured optimized CE was around 65 % with a very homogeneous spatial profile and a SH wave spectral width around 8 nm (corresponding to a FTL pulse duration of around 30 fs). At higher energies, more than 22 mJ at 400 nm has been proved with CE around 40% and a pulse duration of 45 fs (UV Wizzler measurement [4]) behind a grating compressor.

© 2013 IEEE

PDF Article
More Like This
Efficient broadband 400 nm noncollinear second harmonic generation of chirped femtosecond laser pulses in BBO and LBO

O. Gobert, G. Mennerat, R. Maksimenka, N. Fedorov, M. Perdrix, D. Guillaumet, C. Ramond, J. Habib, C. Prigent, D. Vernhet, T. Oksenhendler, and M. Comte
CFIE_P_7 The European Conference on Lasers and Electro-Optics (CLEO/Europe) 2013

High-power High-efficiency Second Harmonic Generation of 1342-nm Laser in LBO and PPKTP

Xing-Yang Cui, Qi Shen, Mei-Chen Yan, Chao Zeng, Tao Yuan, Wen-Zhuo Zhang, Xing-Can Yao, Cheng-Zhi Peng, Xiao Jiang, Yu-Ao Chen, and Jian-Wei Pan
JTu2A.92 CLEO: Applications and Technology (CLEO:A&T) 2019

Improved efficiency of second-harmonic generation in BBO using the 511-nm line of an injection-seeded copper laser

William Molander, Mary Norton, and Jim Chang
CTuW11 Conference on Lasers and Electro-Optics (CLEO:S&I) 1991

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved