Recalibration of the nonlinear optical coefficients of BaGa4Se7 crystal using second-harmonic-generation method

Abstract

Nonlinear optical coefficients are important parameters for nonlinear optical crystals. Based on the previously disclosed BaGa4Se7 crystal coefficients, the optimum phase-matching direction with the largest effective nonlinear optical coefficient appears in the second octant (90∘<θ<180∘, 0∘<ϕ<90∘). In this study, a recalibration was performed using the second-harmonic-generation method, and it was confirmed that the optimum phase-matching direction of the BaGa4Se7 crystal is located in its XZ principal plane (ϕ=0∘). Therefore, this study will serve as a good reference for future applications of this excellent crystal.