United States of America As Represented by the Secretary of the Air Force

Other

Dennis H Goldstein

David B Chenault

Russell A Chipman

Robert R Kallman

Monte Owens

Martin F Wehling

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.

Spectroplarimetric reflectometer

An infrared laser polarimeter system for measuring the Mueller matrix of a sample is described which comprises, a infrared laser source for projecting a beam of preselected wavelength (preferably 3-14 .mu.m) along an optical axis, at least one polarizing element disposed along the axis for linearly polarizing the beam and producing an output beam for analysis, first and second rotatable optical retarders disposed between the source and polarizing element and defining a sample region therebetween, the second retarder being rotated at least five times that for the first retarder, an integrating sphere, and a detector for analyzing the output beam.

Infrared laser polarimeter

A method of performing image correlation in a Fourier transform correlator utilizes phase-encoding of the input image as a phase object with a normalized amplitude component. Phase-only reference image filters are used in conjunction with the phase-encoded input objects to improve the signal to clutter ratio. This technique can employ optical or digital implementation.

Coding intensity images as phase-only images for use in an optical

An infrared spectropolarimeter system for making spectroscopic measurements of electro-optic properties of materials over a large wavelength range in the infrared is described which comprises in combination a spectrometer having a sample region for receiving a sample for making spectroscopic measurements thereon and a source of light for providing a sample beam of selected wavelength for projection through the sample region, the sample region defined between a first focusing element for selectively focusing the sample beam within the sample region and a second focusing element for collimating the sample beam and providing an output beam for analysis, first and second polarizers between the focusing elements with the sample region therebetween for selectively polarizing the sample beam, first and second rotatable optical retarders between the polarizers with the sample region therebetween for selectively retarding one linear polarization component with respect to the orthogonal component of the sample beam, and a detector for analyzing the output beam.

Infrared spectropolarimeter

An achromatic infrared retarder is described which comprises a substrate supporting an optically reflective surface, two identical prisms of preselected optical material disposed in confronting relationship with the reflecting surface therebetween and defining an optical axis through the prisms along which a light beam is selectably directable, each prism having a first optical surface orientable perpendicular to the optical axis, a second optical surface disposed at a preselected angle to the first surface, and a third optical surface disposed at the preselected angle to the second surface, the angle preselected in size corresponding to the material comprising the prisms in order to provide total internal reflection of a light beam directed along the axis at the second surface, the prisms being disposed so as to define a region bounded by respective third optical surfaces of the prisms and the reflective surface therebetween.

Achromatic infrared retarder

A spatial light modulator system having an electro-optic crystal responsive to infrared radiation. An electric field is established across opposed faces of the crystal, and the field is modulated on a point by point basis over one crystal face using a suitable charge distribution write source. Infrared radiation traversing the crystal is modified in polarization in accordance with the pattern imposed on the crystal to simulate an infrared target for testing infrared seekers.

Growing community of inventors

Niceville, FL, United States of America

Dennis H Goldstein