镱离子掺杂硼酸钪晶体生长及脉冲激光性能研究

High energy pulsed lasers possess vital applications in the fields of industrial manufacturing, remote sensing and military confrontation that require intense field. The passive Q-switching conforms to functional, composite and integrated development trends for today’s photoelectric material, but its pulse energy is relatively low, which is the bottleneck restricting its application in pulsed laser devices. .This project is oriented to the need of gain medium for generating high-energy Q-switched laser. Based on the theory of crystal field and solid laser, this project is going to select Yb:ScBO3 crystal with small emission cross-section, long fluorescence lifetime and wide emission spectra. After the initial evaluation, we found that this crystal has excellent energy storage capability and is expected to achieve high-energy pulsed laser. However, the growth of high-quality, optical-grade crystal is very difficult because of factors such as high melting point and strong volatilization.. This project is going to study the Czochralski growth of high-quality Yb:ScBO3 crystal, summarization of the optimal crystal components and growth parameters, the controlment of solid-liquid interface and overcoming the growth difficulties. On this basis, this project will measure the physical properties of the crystal and realize the optimized passively Q-switched laser output. It is going to combine the crystal growth, crystal physics and laser applications. And it will also comprehensively evaluate the overall properties and application prospects, which will lay the foundation for its functionization.

大能量脉冲激光在工业加工、遥感探测和军事对抗等强场光物理领域具有重要应用。被动调Q技术符合当今“功能化”、“复合化”、“结构功能一体化”的发展趋势，但其脉冲能量较低，限制了在脉冲激光器件中的应用范围。.本项目面向大能量被动调Q脉冲激光用关键增益介质，从晶体场及固体激光基本理论出发，优选出小发射截面、长寿命、宽光谱的Yb:ScBO3晶体进行研究。我们对Yb:ScBO3晶体进行了初步评估，表明该晶体储能性能优异，有望实现大能量脉冲激光输出，但受限于高熔点、强挥发等因素，高质量、光学级晶体生长困难。.本项目拟开展高质量Yb:ScBO3晶体的提拉法生长，总结最优生长组分与生长参数，优化温场设计，控制固液界面形状，克服生长难题；并在此基础上，测试晶体的基本物理特性，实现Yb:ScBO3晶体的被动调Q激光优化输出，将晶体生长、晶体物理及激光应用结合，全面评估其综合性能与应用前景，为其实用化奠定基础。

大能量脉冲激光在工业加工、遥感探测和军事对抗等强场光物理领域具有重要应用。可获得大能量脉冲激光的方式主要有调Q或多级放大技术等。相比于多级放大，调Q脉冲技术无需复杂的光学系统和时间同步控制系统，得到广泛应用。本项目面向大能量调Q脉冲激光用关键增益介质，从晶体场及固体激光基本理论出发，优选出小发射截面、长寿命、宽光谱的Yb:ScBO3晶体进行研究，以实现1μm左右的连续二极管端泵调Q激光器的能量突破，促进实际应用。本项目在前期研究的基础上，结合计算机理论模拟，采用提拉法优化生长了高光学质量的Yb:ScBO3晶体。同时，表征了Yb:ScBO3晶体的结构和光谱性能，最大发射截面为0.14×10-20 cm2，荧光寿命为5.51 ms。并在此基础上，实现了Yb:ScBO3晶体的自调Q脉冲激光输出，平均输出功率达332 mW，对应的脉冲宽度、重复频率和脉冲能量分别为731.1 ns、46.1 kHz和7.3 μJ。随后进一步获得声光调Q脉冲激光，最高的单脉冲能量为8.80 mJ，脉冲宽度为80.09 ns，充分证明了其在大能量脉冲激光中的应用潜力。在国内外学术刊物上发表论文5篇，申请发明专利2项（其中授权1项），培养研究生2名。