Intracavity-Pumped, Mid-Infrared Tandem Optical Parametric Oscillator Based on BaGa₄Se₇ Crystal

• Main Authors: Yixin He, Degang Xu, Jiyong Yao, Yuye Wang, Yangwu Guo, Xianli Zhu, Chao Yan, Longhuang Tang, Jining Li, Kai Zhong, Yicheng Wu, Jianquan Yao
• Format: Article
• Language: English
• Published: IEEE 2019-01-01
• Series: IEEE Photonics Journal
• Subjects: Nonlinear crystals (<named-content xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="LaTeX">$\text{BaGa}_4 \text{ Se}_7$</tex-math> </inline-formula> </named-content> crystal); optical parametric oscillator; tunable mid-infrared source
• Online Access: https://ieeexplore.ieee.org/document/8896980/
• ISSN: 1943-0655

We have demonstrated a tunable mid-infrared tandem optical parametric oscillator (OPO) based on BaGa4Se7 (BGSe) crystal, which was intracavity-pumped by the tunable signal wave at ~1 &#x03BC;m generated from a KTiOPO4-OPO (KTP-OPO) in doubly-resonant oscillator (DRO) configuration. Wavelength tuning of the mid-infrared tandem OPO was realized by tuning the pump wavelength at the fixed phase matching angle to reduce the effects of beam cutting and Fresnel reflection loss. Together with pump-tuning method, angle-tuning method was supplied to extend tuning range. A tuning range of 4.1-4.5 &#x03BC;m was obtained with just 5 individual phase matching angles of the BGSe crystal. The maximum output energy of 1.92 mJ/pulse was obtained at 4.26 &#x03BC;m with an estimated slope efficiency of 9.5%.