Thermo-optical properties of LBO crystal for angular non-critical phase matching for second harmonic generation along X-axis

Thermo-optical parameters proved to be very important parameters of crystals for nonlinear optical conversion. These parameters allow defining the temperature bandwidth of phase matching, as well as the temperature tuning characteristics. For lithium triborate (LiB₃O₅, LBO) crystal, there is a possibility to realize the angular non-critical phase matching for second harmonic generation (SHG) along x axis (ssf type of interaction). In this case, one observes both the maximum value of effective nonlinearity coefficient, and the high values of angular bandwidths for two angular coordinates. This possibility is realized in a wide range of wavelengths with variation of crystal temperature.