Open AccessFemtosecond Pulse Generation by Nonlinear Optical Gain Modulation
Author(s) -
Qi Weiao,
Zhou Jiaqi,
Cui Shuzhen,
Cheng Xin,
Zeng Xin,
Feng Yan
Publication year - 2022
Publication title -
advanced photonics research
Language(s) - English
Resource type - Journals
ISSN - 2699-9293
DOI - 10.1002/adpr.202100255
Subject(s) - femtosecond , modulation (music) , optics , nonlinear system , nonlinear optical , materials science , pulse (music) , ultrashort pulse , nonlinear optics , optoelectronics , femtosecond pulse shaping , physics , laser , acoustics , quantum mechanics , detector
Many approaches have been explored to generate ultrafast lasers including mode locking, microresonators, electro‐optic modulation, and gain‐switched diodes. Despite much progress, it is still challenging to generate high‐performance ultrafast pulses with wavelength versatility in a simple approach. Herein, a new method is proposed and demonstrated to transform a continuous‐wave (CW) single‐frequency laser into femtosecond‐scale pulses by nonlinear optical gain modulation in a fiber Raman amplifier. The proof‐of‐principle setup generates a stable and highly coherent laser at 1120 nm with a pulse energy of 25.7 nJ, a pulse width of 436 fs, and an optical efficiency of 69.4% by 14 ps gain modulation. Numerical simulation shows that pulse energy scaling to micro‐Joule level is feasible by increasing pump energy. By cascading the conversion process, high‐energy, femtosecond‐scale pulses can be produced over a wide spectral range.