US 7,002,685 B2 · System for measuring of both circular and linear birefringence

Abstract

A system and method for precisely measuring low-level linear and circular birefringence properties (retardance and direction) of optical materials (26). The system incorporates a photoelastic modulator (24) for modulating polarized light that is then directed through a sample (26). The beam (“Bi”) propagating from the sample is separated into two parts, with one part (“B1”) having a polarization direction different than the polarization direction of the other beam part (“B2”). These separate beam parts are then processed as distinct channels. Detection mechanisms (32, 50) associated with each channel detect the time varying light intensity corresponding to each of the two parts of the beam. This information is combined for calculating a precise measure of the linear and/or circular retardance induced by the sample, as well as the sample's fast axis orientation and direction of circular retardance.

Claims16

Dependent claims

A method of measuring birefringence properties of a sample, comprising the steps of:

modulating polarization of light;
directing a beam of the modulated light through the sample along an incidence path;
reflecting the beam from a reflective surface that is in the incidence path;
analyzing the reflected part of the beam;
determining the intensity of the reflected part of the beam;
calculating a circular birefringence property of the sample based on the determined intensity;
and
passing a first part of the beam through the reflective surface;
determining the intensity of the first part of the beam;
and
calculating a linear birefringence property of the sample based on the determined intensity.

8 more elements

Dependencies are inferred from the claim text.

System for measuring of both circular and linear birefringence

Life of this patent

System for measuring of both circular and linear birefringence

Life of this patent

Abstract

Claims16