Novel non-toxic nonlinear optical crystals for deep-ultraviolet laser generation

深紫外光(DUV)非线性光学(NLO)晶体在先进科学仪器的发展中起着至关重要的作用。该项目的目标是生长新型无毒的DUV NLO晶体，以满足光电子领域日益增长的需求。利用最近发展起来的独特的高压流动溶剂浮动区(TSFZ)炉，将首次用高压TSFZ法生长p高达150bar的NLO单晶。该项目将侧重于与晶体生长、器件和DUV激光器应用相关的关键问题的基础和实验研究。特别是，该项目针对LiBaPO4，LiSrPO4，LiSr0.1Ba0.9PO4，LiSrVO4，LiBaVO4，Ba4B11O20F，Cs2B4SiO9，Li3Cs2B5O10等组成的无毒晶体进行了详细的结构和化学质量研究。与应用相关的单晶的热性质以及它们的线性和非线性光学性质将被详细地研究。将特别强调特定缺陷和光学性质之间的相关性，这些光学性质将被解决以受控的方式产生缺陷，即O和Li缺乏、间隙O或质子辐照。应用的相关性将通过二极管泵浦的DUV固体激光器的原型和获得相干输出的光子能量为6.2-7.8 eV的DUV激光器来演示。此外，预期的结果将有助于更好地了解结构和DUV性能之间的关系，以及新的DUV NLO晶体的开发。

Deep-ultraviolet (DUV) nonlinear optical (NLO) crystals play a crucial role in the development of advanced scientific instruments. The aim of the project is to grow novel non-toxic DUV NLO crystals for fulfilling the increasing demands of the optoelectronics field. A unique high-pressure travelling-solvent floating-zone (TSFZ) furnace which has been developed very recently will be utilized to grow NLO single crystals for the first time by means of the high-pressure TSFZ-method with p up to 150 bar. The project will focus on fundamental and experimental studies related to the critical issues associated with the growth of crystals, devices, and applications of DUV lasers. In particular, the project aims at non-toxic crystals of the compositions LiBaPO4, LiSrPO4, LiSr0.1Ba0.9PO4, LiSrVO4, LiBaVO4, Ba4B11O20F, Cs2B4SiO9, Li3Cs2B5O10, etc. The grown single crystals will be studied in detail regarding their structural and chemical quality. The thermal properties of the single crystals relevant for applications as well as of their linear and nonlinear optical properties will be studied in great detail. Particular emphasis will be given to the correlation between specific defects and the optical properties which will be addressed creating defects in a controlled way, i.e. O and Li deficiency, interstitial O, or proton irradiation. The relevance to application will be demonstrated by a prototype of a DUV diode-pumped solid-state laser and by obtaining a DUV laser with coherent output in photon energy of 6.2-7.8 eV. In addition, the expected results will provide a better understanding of the relationship between structure and DUV properties and of the development of new DUV NLO crystals.