9 μm few-cycle optical parametric chirped-pulse amplifier based on LiGaS2

• Main Authors: Qu, Shizhen, Liang, Houkun, Liu, Kun, Zou, Xiao, Li, Wenkai, 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; Difference-frequency-generation; Midinfrared Pulses
• Online Access: https://hdl.handle.net/10356/147094
• Institution: Nanyang Technological University

We report a long-wavelength mid-infrared (mid-IR), few-cycle optical parametric chirped-pulse amplifier (OPCPA) based on LiGaS2 crystals, pumped by a 1 μm Yb:YAG laser, at a 10 kHz repetition rate. The mid-IR OPCPA system generates pulses centered at 9 μm, with 1 4 μJ pulse energy and 140 mW average power. A 142 fs pulse width, which corresponds to less than 5 optical cycles at 9 μm, is measured by an interferometric autocorrelator. This is, to the best of our knowledge, the first long-wavelength mid-IR OPCPA pumped at 1 μm wavelength. It paves the way for the energy and power scaling of the ultrafast long-wavelength mid-IR lasers by utilizing advanced high-energy, high-power 1 μm pump lasers.