The vacuum ultraviolet phase‐matching characteristics of nonlinear optical KBe2BO3F2 crystal

The nonlinear optical crystal KBe2BO3F2 has been used to produce vacuum ultraviolet second‐harmonic generation with an output range of 200–184.7 nm. The Sellmeier equation further indicates that this new crystal can generate the sixth harmonic from Nd‐based laser systems.