Spectroplarimetric reflectometer
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsDennis H. Goldstein, David B. Chenault, Monte Owens
Life of this patent
Estimating the term…
Abstract
A spectropolarimetric reflectometer for measuring polarimetric reflection properties of materials over broad spectral wavelength regions is described wherein radiation from a Fourier transform spectrometer passes through a set of polarization elements that serve as a polarization state generator and is reflected off the sample and collected by optics that includes a polarization state analyzer, focusing mirror and detector.
Claims15
A bistatic spectropolarimetric reflectometer system for measuring polarimetric reflection properties of a material over broad spectral wavelength regions, comprising:
- (a) a radiation source for generating radiation over a predetermined broad spectral range from the ultraviolet to the infrared and directing a beam of said radiation along an optical axis;
- (b) an optical detector;
- (c) a rotatable platform for supporting a sample of material substantially centrally thereon, and means operatively connected to said platform for selectively rotating said platform;
- (d) first set of polarization elements defining a polarization state generator and including a rotatable linear polarizer followed by a rotatable quarter wave retarder, said polarization state generator disposed along said optical axis for directing said beam onto the sample;
- (e) a second set of polarization elements defining a polarization state analyzer and including a rotatable quarter wave retarder followed by a rotatable linear polarizer, said polarization state analyzer disposed along said optical axis for directing the entire spectral range of said beam reflected from the sample onto said detector;
- and
- (f) wherein said detector includes means for processing said beam and providing data output including the Mueller matrix of the sample.
A monostatic spectropolarimetric reflectometer system for measuring polarimetric reflection properties of a material over broad spectral wavelength regions, comprising:
- (a) a radiation source for generating radiation over a predetermined broad spectral range from the ultraviolet to the infrared and directing a beam of said radiation along an optical axis;
- (b) an optical detector;
- (c) a rotatable platform for supporting a sample of material substantially centrally thereon, and means operatively connected to said platform for selectively rotating said platform;
- (d) first set of polarization elements defining a polarization state generator and including a rotatable linear polarizer followed by a rotatable quarter wave retarder, said polarization state generator disposed along said optical axis between said source and the sample;
- (e) a second set of polarization elements defining a polarization state analyzer and including a rotatable quarter wave retarder followed by a rotatable linear polarizer, said polarization state analyzer disposed along said optical axis between the sample and said detector;
- (f) a beamsplitter disposed along said optical axis between said polarization state generator and the sample for directing the entire spectral range of said beam from said polarization state generator onto the sample and for directing the entire spectral range of said beam projected by said polarization state analyzer onto said detector;
- and
- (g) wherein said detector includes means for processing said beam and providing data output including the Mueller matrix of the sample.
Dependencies are inferred from the claim text.