钕钒共掺钇镓石榴石晶体生长及其1.4微米人眼安全波段自调Q脉冲激光研究

1.4-1.8 µm lasers are located at the eye-safe region and an atmospheric transmission window, and due to the high peak power and large pulse energy, its corresponding pulsed lasers have vital applications in the fields of medical treatment, laser radar and remote sensing measurement. For pulsed lasers in this band region, the functional devices with the compact structure design and simple operation are the ideal selection. Following with the composite and integrated development trends of functional materials, in this research project, by making the Nd3+ gain ions and V3+ modulation ions co-doped in the yttrium gallium garnet (Nd,V:YGG) crystal with the high thermal conductivity and low host phonon energy, we propose to develop the functional composite between gain media and optical switches, and carry out the research on the self-Q-switched laser at 1.4 µm. By studying the crystal growth of Nd,V:YGG crystals, interaction mechanism between Nd3+ and V3+ ions, and influence between the doped concentration and proportion of both ions and basic physical properties, design the relevant functional devices, and realize the Nd,V:YGG self-Q-switched laser at 1.4 µm. Then, combine the crystal growth, basic physical properties and design of laser devices, promote the pulsed laser performance by the cycle optimization, and finally evaluate its comprehensive properties and application prospect. The research work in this project would lay the foundation for the development of eye-safe pulse lasers with functional composite and integration in this band region.

1.4-1.8 µm激光属人眼安全波段，且处于大气传输窗口之一，其脉冲激光具有峰值功率高与脉冲能量大的优势，在医疗、激光雷达和遥感测量等军用及民用领域具有重大需求。结构简单、紧凑，操作简易的功能器件是此波段脉冲激光的理想选择。本项目顺应功能材料“复合化”与“材料器件一体化”的发展趋势，提出将Nd3+增益离子与V3+调制离子共掺于具有高热导率与低基质声子能量的钇镓石榴石（Nd,V:YGG）晶体中，开展增益介质和光开关调制器件功能复合的1.4 µm自调Q脉冲激光研究。通过探究Nd,V:YGG的晶体生长、Nd3+与V3+离子之间相互作用机理和掺杂浓度与基本物理特性的影响规律，设计相应功能器件，实现1.4 µm自调Q脉冲激光输出；然后，将晶体生长、基本物理特性和激光器设计相结合，进行循环优化，评估其综合性能与应用前景，为此波段功能复合化和集成小型化人眼安全脉冲激光器开发奠定基础。

1.4-1.8 µm人眼安全波段激光在医疗、激光雷达和遥感测量等领域具有重大需求。本项目顺应功能材料“复合化”与“材料器件一体化”的发展趋势，提出将Nd3+增益离子与V3+调制离子共掺于钇镓石榴石 (Nd,V:YGG) 晶体中，开展1.4 µm自调Q脉冲激光研究。在Nd,V:YGG晶体生长研究中，通过多晶粉料中源于钒掺杂的杂相问题、光学浮区法晶体生长与退火处理工艺优化等研究工作，实现了不同掺杂组分的高质量Nd,V:YGG晶体制备，并提供了完整晶体生长工艺报告；在此基础之上，明确了所制备晶体中钒离子种类 (八面体与四面体中V3+与V4+离子)，分析了钕与钒离子之间相互作用机理，总结了不同钕与钒离子掺杂浓度及比例对Nd,V:YGG晶体结构、组分、热学与光学等基本物理特性的影响规律；然后，通过自调Q晶体与激光谐振腔的设计优化 (包括晶体长度、离子掺杂浓度、泵浦光源与谐振腔设计等)，实现了脉冲宽度为24 ns，峰值功率为0.98 kW的1.4 µm自调Q脉冲激光输出。本项目研究不仅有利于此波段功能晶体材料的开发，而且还为功能复合化和集成小型化脉冲激光器开发提供了有利支撑。