Finding a Novel Borate Ferroelectric with Random Domain Structures for Deep‐UV Quasi‐Phase‐Matching
Yabo Wu, Cui Chen, Zhongchang Wang, Junjie Li, Jian Han, Miriding Mutailipu, Shilie Pan
Abstract
Abstract Finding competitive nonlinear optical (NLO) crystals for practical deep‐ultraviolet (deep‐UV) lasers remains a fundamental yet challenging goal in photonic materials research. The production of deep‐UV lasers through the mesoscopic domain structure of ferroelectric materials has been a popular research area via quasi‐phase‐matching (QPM). However, as of right present, no ferroelectric in the deep‐UV area is able to provide QPM laser output. Here, a new room‐temperature borate ferroelectric Ba 3 Mg 3 (BO 3 ) 3 F 3 (BMBF) is presented. The ferroelectricity of BMBF crystals exhibits significant relaxor behavior and the random domain structure can relax the strict phase‐matching conditions, rendering it a disordered NLO medium. Benefiting from its unique ferroelectric properties, BMBF crystal achieves a second‐harmonic generation output energy of 3.55 µJ for 398 to 199 nm wavelength frequency conversion, even in the absence of birefringent phase‐matching conditions. This result demonstrates that BMBF is a promising candidate for deep‐UV QPM applications. Furthermore, this study expands the frontiers of borate ferroelectrics while the realization of deep‐UV light output using BMBF crystal motivates and provides a path for its broader application.