Spectral programmable mid-infrared optical parametric oscillator

• junrui Liang, Xu Jiangming, Yanzhao Ke, li sicheng, Junhong He, Yidong Guo, Yang Zhang, Xiao Ma, Jun Ye, Xiao Li, Jinyong Leng, and Pu Zhou
• received 03/19/2024; accepted 05/08/2024; posted 05/09/2024; Doc. ID 524117
• Abstract: A spectral programmable, continuous-wave mid-infrared (MIR) optical parametric oscillator (OPO) was proposed and realized, enabled by a self-developed high-power spectral tailorable fiber laser. While operating at single-wavelength, the maximum idler power reached 5.53 W at 3028 nm, with a corresponding pump-to-idler conversion efficiency of 14.7%. Wavelength number switchable output was available from one to three. The single idler was tunable in a range of 528 nm (2852~3380 nm). In dual-wavelength operation, the interval between two idlers could be flexibly tuned for 470 nm (53~5 nm), and the intensity of each channel was controllable. Triple-wavelength idler emission was realized, meanwhile exhibiting spectral custom-tailored characteristics. Furthermore, we balanced the parametric gain through pre-modulating broadband multi-peak pump spectra, enabling a 10 dB bandwidth adjustment of the idler emission from 20 to 125 nm. This versatile mid-infrared laser, simultaneously featuring wide tuning, multi-wavelength operation, and broad bandwidth manipulation, has great application potential in composition detection, terahertz generation, and speckle-free imaging.