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

深紫外非线性光学晶体（NLO）在先进科学仪器的发展中起着至关重要的作用。该项目的目标是培育新型无毒DUV NLO晶体，以满足光电子领域日益增长的需求。本文将首次利用新开发的一种独特的高压流动溶剂浮选区（TSFZ）炉，采用高压TSFZ法生长NLO单晶，温度高达150 bar。该项目将侧重于与晶体、器件和DUV激光器应用相关的关键问题的基础和实验研究。该项目特别针对LiBaPO4、LiSrPO4、LiSr0.1Ba0.9PO4、LiSrVO4、LiBaVO4、Ba4B11O20F、Cs2B4SiO9、Li3Cs2B5O10等成分的无毒晶体。对生长的单晶进行结构和化学性质的详细研究。本文将详细研究与应用相关的单晶的热性质及其线性和非线性光学性质。特别强调的是特定缺陷与光学性质之间的相关性，这将以受控的方式解决产生缺陷的问题，即O和Li缺乏症，间隙O或质子辐照。将通过DUV二极管泵浦固体激光器的原型和获得光子能量相干输出为6.2-7.8 eV的DUV激光器来证明其与应用的相关性。此外，预期的结果将为更好地理解结构与DUV性能之间的关系以及新型DUV NLO晶体的开发提供帮助。

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.