Patent ID: 8854623

Claim:
A system for performing a refracted near-field (RNF) measurement of a profile characteristic of a glass sample disposed adjacent a reference block having a top surface, comprising: a light-source system that generates polarized light; a polarization-switching system that receives and switches the polarization of the polarized light between first and second orthogonal polarizations to form a polarization-switched light beam; a reference detector system arranged to receive a portion of the polarization-switched light beam and form a polarization-switched reference detector signal; an optical system configured to scan the polarized-switched light beam through the glass sample and the reference block at different depths into the glass sample; a signal detector system arranged to receive, over an angular range within 26° to 45° relative to normal incidence, the polarization-switched light beam transmitted through the glass sample and the reference block, and form in response a polarization-switched detector signal; and a signal-control-and-processing system operably configured to move the reference block and sample and receive and process the polarization-switched reference and detector signals to determine a profile characteristic of the glass sample.