Interferometrically measuring phase mismatch for second harmonic generation

A new measuring technique has been developed to analyze the phase matching performance of potential second harmonic generators. Data are in the form of interferograms produced by a self-referencing nonlinear optical interferometer. These measurements allow prediction of phase matching temperatures for noncritically phase matchable materials and crystal orientations for angle tuned materials, both in types I and II configurations. Phase mismatch measurements were made at a fundamental wavelength of 1.32 μm for lithium niobate and gadolinium molybdate. This technique is shown to predict correctly when phase matching will occur.