Swept wavelength reflectometer for integrated-opticmeasurements

The experimental investigation of a high-resolution optical reflectometry technique based on the thermally induced sweep of sample refractive index is described. Reflections from surface scratches and the end surfaces of a Ti:LiNbO(3) waveguide were detected with a resolution of <0.2 mm, which is sufficient for the characterization of reflections in integrated-optic devices. Improvement in the dynamic range of the measurement is required for the detection of well-fabricated waveguide features such as bends and Y junctions. Several possibilities exist for making this improvement.