Absorption Loss In Ti:LiNb03-Stripe Waveguides A New Measurement Technique

A novel nondestructive technique to measure the intrinsic absorption-loss spectra of TiliNb03- stripe waveguides is demonstrated. The principle of operation is to generate periodic heat waves by light-absorption in a stripe waveguide and to calculate its absorption coefficient from the measured temperature changes in a parallel waveguide resonator. The lowest measured absorption coefficient in the spectral range of 633-730nm was a = 0.002dB/cm at A = 730nm (HE-polarization). A resolution of 10 -4 dB/cm at 700nm and 2.9mW excite power was achieved.