1 河北工业大学电子信息工程学院先进激光技术研究中心，天津 300401
2 河北工业大学河北省先进激光技术与装备重点实验室，天津 300401
3 哈尔滨工业大学可调谐激光技术国家重点实验室，黑龙江 哈尔滨 150080
利用中心波长为800 nm、脉冲宽度为35 fs的飞秒激光脉冲开展了以蓝宝石晶体为介质的超连续白光光谱特性研究，通过对比不同入射脉冲能量下焦距为40 mm的球面透镜产生的白光光谱发现：随着入射脉冲能量的增强，白光光谱向蓝边方向展宽，当能量增加到210 nJ时，光谱范围不再变化。对比焦距为40 mm的球面透镜和消色差透镜产生的白光光谱发现：消色差透镜产生的光谱的整体强度小于球面透镜，且光谱有一定蓝移，蓝移波长可达450 nm。采用Zemax软件对两种透镜产生的焦斑进行仿真，比较了两种透镜产生的焦斑的大小和能量，并分析了蓝移现象产生的原因。同时，本研究对比了焦距为40 mm和100 mm球面透镜、消色差透镜产生的白光光谱的范围和稳定性，结果表明，焦距为40 mm的透镜产生的白光光谱的稳定性较好，光谱范围较宽，约为450～700 nm。罗丹明B的瞬态吸收实验结果表明，使用焦距为40 mm的消色差透镜时，罗丹明B的瞬态吸收信号最为明显，信噪比最高。本实验表明，针对不同的样品特性，可以通过选择不同的透镜来优化瞬态吸收实验结果。
非线性光学 飞秒激光 超连续白光 瞬态吸收 中国激光
2022, 49(11): 1111003
1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
3 上海科技大学, 上海 201210
研制了一套能量输出稳定、光斑分布均匀、时域近方波形的四路钕玻璃抽运源系统。系统能够输出4×180 J的基频能量(波长为1053 nm)，4×80 J的倍频能量(波长为526.5 nm)。主要结构包括四部分：前端种子源、再生放大器、钕玻璃棒放链和KDP倍频晶体。利用偏振片实现了垂直偏振的两路基频光合束，经过第二类相位匹配KDP晶体倍频，获得了共线且同偏振的526.5 nm倍频光，实现了用于150 mm口径钛宝石放大器的结构紧凑的双脉冲抽运源。
激光器 放大器 抽运源 钕玻璃 大口径钛宝石 时域双脉冲
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
A Ti:sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method (HEM). The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit (FOMs) at different positions of the crystal were measured and the FOM value in the central region was found to reach 90. The transmittance laser beam was intact with no obvious distortions and had only a small deformation compared with the incident laser beam. A small-signal amplification experiment was performed on the Ti:sapphire crystal and a gain of more than 6 times was achieved with a pump energy density of 1.98 J/cm2. These tests indicate that the 235 mm Ti:sapphire crystal has excellent optical qualities and will further improve the energy output of a 10 PW laser system.
140.3280 Laser amplifiers 140.3590 Lasers, titanium 140.5560 Pumping Chinese Optics Letters
2018, 16(7): 071401
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 ShanghaiTech University, Shanghai 200120, China
3 University of Chinese Academy of Sciences, Beijing 100039, China
We research some properties of parasitic lasing (PL) in the Ti:sapphire chirped pulse amplifier with the crystal diameter of 100 mm. The evolutionary process from the spontaneous emission to the PL and its influence on amplified output energy, spectrum, and beam profile are experimentally measured. The threshold of PL in the crystal is 22 J, and the output signal can still keep rising with the pump when the pump energy is below 38 J. The PL has no obvious impact on the output spectrum and beam profile besides the energy.
140.3280 Laser amplifiers 140.3590 Lasers, titanium 140.5560 Pumping Chinese Optics Letters
2017, 15(6): 061401
