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

• Applicant: Jianxiu Zhang, Ph.D.
• Subject Area: Synthesis and Properties of Functional Materials ; Experimental Condensed Matter Physics
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 255837079

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.

• DFG Programme: Research Grants
• Participating Persons: Klaus Irmscher, Ph.D.; Professor Dr. Rüdiger Klingeler; Reinhard Uecker, Ph.D.