A HIGH RESOLUTION REAL-TIME TEMPORAL HETERODYNE INTERFEROMETER FOR REFRACTIVE INDEX TOPOGRAPHY

摘要

A Mach-Zehnder interferometer for two-dimensional refractive index topography is presented which utilizes the temporal heterodyne technique. High scanning rates and excellent phase resolutions are obtained using an image dissector camera and a lock-in amplifier. The setup is applied for investigation of the photorefractive effect. A macroscopic light pattern is recorded and thermally fixed in iron-doped LiNbO3. The evolution of the refractive index pattern during development by homogeneous illumination is observed with the interferometer. The measured refractive index profiles are in good agreement with the results of computer simulations. (C) 1997 Elsevier Science B.V. [References: 23]