Polarization-dependent nonlinear refractive index of BiB3O6

The nonlinear refractive index of the monoclinic biaxial nonlinear crystal BiB3O6 (BIBO) was measured at 1064 nm for light polarization along the three principal optical axes using the single-beam z-scan technique. Strong anisotropy was observed with n2 values about two-times larger for polarization parallel to the Z-axis in comparison to the X-axis. BIBO exhibits lower nonlinear refractive index than KTP although its effective nonlinearity is larger.