Core Viewpoint - The research team from the Xinjiang Institute of Physics and Technology has successfully developed a new nonlinear optical crystal, ammonium borofluoride (ABF), achieving a record shortest output wavelength of 158.9 nanometers for vacuum ultraviolet laser through birefringent phase matching technology [1] Group 1: Development and Innovation - The ABF crystal is a key material for achieving all-solid-state vacuum ultraviolet laser output, with its performance determining the output wavelength and conversion efficiency of lasers [1] - The team proposed an innovative design and performance tuning mechanism for vacuum ultraviolet nonlinear optical crystals, creating a series of high-performance crystals represented by ABF [1] Group 2: Technical Achievements - The researchers overcame challenges in crystal growth and device processing technology, successfully obtaining centimeter-level high optical quality ABF single crystals and vacuum ultraviolet frequency doubling devices [1] - Test results indicate that the ABF crystal has set three world records in direct frequency doubling vacuum ultraviolet laser output: the shortest output wavelength, the highest nanosecond pulse energy of 177 nanometers, and significantly improved optical-to-optical conversion efficiency, with overall performance far exceeding existing materials [1]