Abstract

There is a large discrepancy in currently accepted absolute values of second-harmonic generation (SHG) coefficients [1]. The discrepancy indicates that careful and accurate measurements using well-characterized laser sources are needed. Recently, Eckardt et al. performed measurements of absolute magnitudes of the phase-matchable nonlinear coefficients of several crystals using a pulsed Nd:YAG laser and pointed out that part of absolute values accepted as standards to date are erroneous [2]. In this paper, we report the accurate measurements of absolute SHG coefficients of lithium niobate (LiNbO₃) using a high-quality semiconductor laser diode as a fundamental light source. This includes the first absolute measurement of the non-phase-matchable coefficient, d₃₃, of this material. d₃₃, the largest coefficient of LiNbO₃, is an important parameter which determines performance of waveguiding frequency conversion devices.

© 1992 Optical Society of America