An interlinked prediction-experiment paradigm discovering deep-ultraviolet fluorooxoborates with desired optical nonlinearity and birefringence

Exploring new materials that meet urgent needs via advanced paradigms is still a challenge. Herein, aiming at deep-ultraviolet optical functional materials with targeted properties including deep-ultraviolet transparency and high optical properties, we report an optical materials discovery paradigm—an interlinked prediction-experiment strategy. Novel fluorooxoborate crystals in the NaB4O6F system are predicted successfully, which realizes a balance between deep-ultraviolet transparency and large birefringence or deep-ultraviolet phase-matching wavelengths and strong nonlinear optical response. Concurrently, the experimentally oriented preparation of a new crystal NaB4O6F-C2/c and the known compound NaB4O6F-C2 is achieved, confirming the validity of the paradigm. Further results indicate that NaB4O6F-C2/c is a new-generation birefringent crystal with large birefringence (0.219@193 nm) and deep-ultraviolet transparency, and the phase-matching curves of NaB4O6F-C2 show the shortest phase-matching wavelengths for type I and type II, 166 and 200 nm. This research has enabled the customization of functional materials with high performances via the interlinked discovery paradigm.