【作者】 钟艳；

【导师】 何京良；

【作者基本信息】 山东师范大学 ， 光学， 2007， 硕士

【摘要】 1.57μm激光,既对人眼安全,又能全天候工作,且对烟雾的穿透能力强,从而在光电对抗、激光测距、跟踪、预警等军事领域显示出其优良的性能。尤其通过OPO技术获得1.57μm激光因具有效率高、体积小,可高重复频率工作的特点,近几年发展十分迅速,被广泛应用于激光加工、外科手术、激光雷达和激光精确制导等领域。本论文围绕1.57μm人眼安全波长光学参量振荡器进行了理论和实验研究。论文主要内容概括为:1.概括了OPO的发展历史与人眼安全KTP-OPO研究现状,介绍了1.57μmOPO激光的技术优势。2.综述了光学非线性波长变换技术,介绍了二次非线性极化变频作用及三波混频耦合波方程,总结了光学参量振荡工作原理。3.分析总结了Nd:YVO₄与Nd:GdVO₄晶体的激光特性,并通过实验研究了LD泵浦声光调Q Nd:YVO₄1064nm激光输出特性。4.分别选用声光调Q Nd:YVO₄激光及Nd:GdVO₄激光作为泵浦光,以II类非临界相位匹配KTP晶体作为非线性增益介质,采用内腔式泵浦结构及单谐振运转方式,实现了两种KTP光参量振荡器激光运转,获得了405mW的1.57μm激光输出,此时注入泵浦功率为6.33W,重复频率为15kHz,峰值功率达10.8kW,脉宽为2.5ns;重复频率5kHz时,脉宽最窄为2ns。5.介绍了新型晶体KTA的基本特性及角度相位匹配方式,选用声光调Q Nd:YVO₄激光器作为泵浦源,以KTA晶体为非线性增益介质,实现了KTA-OPO激光运转,在注入泵浦功率6.35W,重复频率20kHz时,获得输出功率424mW,脉宽2.5ns,峰值功率8.48kW的1.57μm激光输出。更多还原

【Abstract】 1.57μm eye-safe wavelength lasers, because of their advantages such as eye -safe ,all-weather operation, pass through smoke and so on, are vital for applications in the field of military involving photoelectricity counterwork,laser rangefinder , scout , obstacle avoidance and etc. Especially the 1.57μm lasers obtained by technology of optical parametric oscillator, have become a central of focus in the fields of laser process ,surgical ,laser radar ,laser-guided and so on due to their many advantages, such as higher conversion efficiency, compactness and higher pulse repetition rate and etc. This dissertation presents results of theoretical and experimental researches on optical parametric oscillator at 1.57μm eye-safe wavelength. The contents can be outlined as follows:1. The history and development of optical parametric oscillator are reviewed. The main approaches and new results of eye-safe wavelength KTP-OPO at present are summarized,The advantages of optical parametric oscillator at 1.57μm eye-safe wavelength are introduced.2. Introducing the theory of nonlinear wavelength transform technology, second nonlinear polarization frequency transform and the coupling equations of three nonlinear frequencies mixing. The theory of optical parametric oscillator is summarized.3. Analyzing the characters of laser crystals of Nd:YVO₄ and Nd:GdVO₄.The output characters of LD pump acoustic-optical Q-switched Nd:YVO₄ 1064nm laser is investigated by experiments.4. Two efficient, eye-safe wavelength, intracavity single-resonance optical parametric oscillators, based on a type II non-critical phase-matched KTP crystal, inside a Q-switched laser end pumped by a fiber-coupled diode laser are demonstrated. When the incident pumping power was 6.33W, we obtained 405mW 1.57μm eye-safe wavelength at 15 kHz repetition rate with pulse duration of 2.5ns and peak power of 10.8kW. And minimum of pulse duration of 2ns has been obtained at 5 kHz repetition rate.5. The characters and the angle phase matching of the new type KTA crystal are introduced .The intracavity optical parametric oscillator based on a KTA crystal inside an acoustic-optical Q-switched Nd:YVO₄ laser end pumped by a fiber-coupled diode laser are demonstrated. When the incident pumping power was 6.35W, 424mW 1.57μm eye-safe wavelength was obtained at 20 kHz repetition rate with pulse duration of 2.5ns and peak power of 8.48kW.更多还原