Refractive-index temperature derivatives of potassium titanyl phosphate

Measurements of the refractive-index temperature derivatives at nine wavelengths between 502 and 1129 nm in flux-grown potassium titanyl phosphate are reported. Based on the measurements, we derive three equations that describe the derivatives' wavelength dependence. Values obtained with these equations are in good agreement with both retardation measurement results and observed phase-matching temperature bandwidths for various nonlinear interactions, indicating an error smaller than +/-1 x 10(-6)/ degrees C. At a wavelength of 1064 nm the derivatives are calculated as partial differentialn(x)/ partial differentialT = 6.1 x 10(-6)/ degrees C, partial differentialn(y)/ partial differentialT = 8.3 x 10(-6)/ degrees C, and partial differentialn(z)/ partial differentialT = 14.5 x 10(-6)/ degrees C.