Fabry-Perot resonator apparatus and method for observing low reflectivity surfaces

摘要

A Fabry-Perot resonator apparatus and method for observing low reflectivity surfaces provides functional improvements for optical inspection and measurement systems, optical storage and retrieval systems as well as other optical systems when the a surface of interest in the resonator path has a lower than ideal reflectivity. The Fabry-Perot resonator is designed with an angle of incidence on the surface of interest deviating from normal incidence, effectively raising the reflectivity. Resonance is supported either by one or more reflectors oriented at angles with respect to the surface of interest, or by a focusing system that alters the directive angle of optical path(s) within the resonator such that the angle of incidence at an intersection of the optical path with the surface of interest is an angle other than normal. A normal incidence is maintained at the reflector(s), so that resonance is supported between the surface of interest and the reflector(s).