Abstract

Earlier [1] we have reported application of the photo-EMF based adaptive detectors for coherence measurements of the laser beams, including those reflected from rough surfaces. Later [2], application of this technique for laser profilometry of as-processed metal surfaces was experimentally demonstrated. Here we present for the first time, micron resolution monitoring of in-depth distribution of the reflectance i e, another step to application of this technique to Optical Coherence Tomography. The technique is based on direct detection of the photo-EMF signal amplitude, generated by the laser source with low coherence as a function of the optical path delay between the interfering optical beams - Fig. 1. One or both of the beams can have complicated wavefronts, which can potentially increase efficiency of the light collecting in case of real (not polished) objects and improve the signal-to noise ratio in the output signal.

© 2000 IEEE