Spatially selective enhancement of random quasi phase matched conversion in strontium tetraborate

https://doi.org/10.1016/j.optcom.2025.132836

Orthorhombic strontium tetraborate (α-SBO) is a prospective optical material for future high-power applications in DUV and VUV. Limitations of α-SBO as a nonlinear optical material can be overridden by the use of spontaneous random domain structures inherent to this unique material. The present article reports spatially selective random quasi phase matching of nonlinear optical conversion in random structures of α-SBO that resulted in more than two orders of magnitude efficiency enhancement for the frequency doubling to the blue spectral region due to employing excellent radiation damage resistance of α-SBO and selection of most efficient parts of random structure. Further progress to DUV and VUV generation is prognosed via the development of technology in the direction of obtaining thinner average thickness of domains.