基于闲频光谐振的中红外高能量、高光束质量KTiOAsO_(4)光学参量振荡器  

High Energy,High Beam Quality Idler-resonant mid-infrared Optical Parametric Oscillator Based on KTiOAsO_(4)

作　　者：周玉霞 艾孜合尔江·阿布力克木 达娜·加山尔 塔西买提·玉苏甫[1] ZHOU Yuxia;Aiziheerjiang Abulikemu;Dana Jiashaner;Taximaiti Yusufu(Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials,School of Physics and Electronic Engineering,Xinjiang Normal University,Urumqi 830054,China)

机构地区：[1]新疆师范大学物理与电子工程学院新疆发光矿物与光功能材料研究重点实验室,乌鲁木齐830054

出　　处：《光子学报》2023年第2期46-52,共7页Acta Photonica Sinica

基　　金：国家自然科学基金(No.11664041),新疆维吾尔自治区自然科学基金(No.2021D01A114),新疆矿物发光材料及其微结构实验室(No.KWFG202202)。

摘　　要：基于砷酸钛氧钾(KTA)晶体优良的非线性光学特性,研究了由1μm Nd:YAG纳秒脉冲调Q激光器泵浦的高能量、高光束质量闲频光单谐振光参量振荡器。选取合适镀膜参数的腔镜、优化腔型设计,建立了一个稳定紧凑的半球形对称闲频光单谐振腔,实现了高能量、高光束质量的近-中红外激光输出。在输入泵浦光的(1.064μm)最大能量为20.2 mJ时,输出信号光(1.535μm)和闲频光(3.468μm)的最大能量分别为2.91 mJ和1.13 mJ,对应信号光和闲频光的斜效率分别为20.9%和8.1%。闲频光单谐振的光参量振荡器具有更大的衍射损耗和光束发散角,可以极大的限制输出光束的光谱带宽、提高谐振闲频光的光束质量等优势,测量了输出中红外闲频光在两个正交方向上的光束质量因子分别为M_(x)^(2)≈1.1,M_(y)^(2)≈1.1。The high energy,high beam quality mid-infrared lasers(3~5μm),located in the most transparent atmospheric window band,including super-resolution molecular absorption microscopy,molecular spectroscopy,remote sensing,infrared countermeasures,military,and medical treatments,have been widely investigated for a wide variety of applications.In this research,we report on a high energy,high beam quality idler-resonant mid-infrared Optical Parametric Oscillator(OPO)based on a KTiOAsO_(4) and pumped by a conventional Q-switched Nd:YAG laser.The all solid state Q-switched Nd:YAG laser wavelength at 1.064μm(25 ns,50 Hz,and 20 mJ)was used as a pump source,its nearly Gaussian spatial formed output was loosely focused a waist radius ofω0=500μm to the center of the crystal.A Half-Wave Plate(HWP)and a Thin-Film Polarizer(TFP)were used to control the pump energy injected into the OPO.The idler-resonant oscillator compromised of a concave input mirror(R=500 mm)with antireflection for pump and high-reflection for signal and idler outputs,and a plane output coupler with partial reflection(R=80%)for idler output,and high transmission to the pump and signal outputs.The physical length of this nearly half-symmetric OPO cavity was fixed~35 mm.The compact half symmetric-stable cavity with appropriate radius curvature of the cavity mirrors provided high efficiency near-and mid-infrared generation.The KTiOAsO_(4)crystal as a nonlinear parametric gain medium has high transmission in the 3~5μm region,it was cut along its X-axis(θ=90°,φ=0°)to realize typeⅡNoncritical Phase Matching(NCPM)among pump,signal and idler outputs.A Ge filter is used to filter out the signal and undepleted pump beam from the idler output.We recorded the spatial form of pump beam using a conventional CCD camera,a Spiricon pyroelectric camera was also used to observe spatial forms of the signal and idler outputs.With this idler-resonant OPO,we have obtained 2.91 mJ of 1.535μm nearinfrared and 1.13 mJ of 3.468μm mid-infrared energy outputs at the maximum pump

关 键 词：非线性光学 闲频光谐振 光参量振荡器 光束质量 砷酸钛氧钾 

分 类 号：O437.4[机械工程—光学工程]