Deep-ultraviolet nonlinear optical crystals by design: A computer-aided modeling blueprint from first principles

Deep-ultraviolet (DUV) nonlinear optical (NLO) crystal is indispensable in current DUV all-solid-state laser technology, which is the key device to generate DUV light by frequency conversion. Due to stringent criteria, DUV NLO crystals are scarce and their discovery faces a big challenge. Although KBe2BO3F2 (KBBF) is already excellent for current uses, the development of DUV science requires the materials with shorter output wavelengths and larger NLO effects, so as to meet the needs of DUV lasers with higher precision and higher power. Therefore, how to efficiently design DUV NLO materials has always been the core issue in NLO materials science. Looking back on the development of NLO materials, it turns out that theoretical modeling and simulation is an effective and efficient method, not only for mechanism understandings, but also for experimental exploration. In this article, in order to accelerate the process of DUV materials discovery, we summarize and propose a powerful computeraided modeling system and design blueprint that can be used to evaluate the DUV NLO performance in a faster way than pure experiments. With this in hand, we enrich the understanding of NLO structure-property correlation, and systematically prospect the DUV NLO properties on the basis of many existing and designed structures according to different structural types and chemical compositions. Seven novel structures are predicted for the first time to exhibit potential DUV NLO capabilities. All the results enable us to believe that the computer-aided modeling blueprint will play an important role in the exploration of new DUV NLO crystals.