Multimicrojoule GaSe-based midinfrared optical parametric amplifier with an ultrabroad idler spectrum covering 4.2-16 μm

• Main Authors: Liu, Kun, Liang, Houkun, Wang, Lifeng, Qu, Shizhen, Lang, Tino, Li, Hao, Wang, Qi Jie, Zhang, Ying
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics; Difference-frequency-generation; Pulses
• Online Access: https://hdl.handle.net/10356/147092
• Institution: Nanyang Technological University

We report a multimicrojoule, ultrabroadband midinfrared optical parametric amplifier based on a GaSe nonlinear crystal pumped at ∼2 μm. The generated idler pulse has a flat spectrum spanning from 4.5 to 13.3 μm at -3 dB and 4.2 to 16 μm in the full spectral range, with a central wavelength of 8.8 μm. The proposed scheme supports a subcycle Fourier-transform-limited pulse width. A (2+1)-dimensional numerical simulation is employed to reproduce the obtained idler spectrum. To our best knowledge, this is the broadest -3 dB spectrum ever obtained by optical parametric amplifiers in this spectral region. The idler pulse energy is ∼3.4 μJ with a conversion efficiency of ∼2% from the ∼2 μm pump to the idler pulse.