The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 1990
Filed:
Jun. 14, 1989
Russell Chipman, Madison, AL (US);
David Chenault, Huntsville, AL (US);
The University of Alabama in Huntsville, Huntsville, AL (US);
Abstract
An infrared achromatic waveplate structure having a cadmium sulfide (CdS) plate and a cadmium selenide (CdSe) plate aligned with each other so that the fast axis of the plates are perpendicular to each other, this structure provides a desired retardance of a first orthogonal polarization component with respect to a second orthogonal polarization component of an incident light beam. The thickness of the plates are in a ratio between 0.8:1 and 0.9:1 (CdSe:CdS), an achromatic response with a substantially constant retardance is provided in a wavelength range from 3 to 11 microns. A desired amount of retardance is available by adjusting the thickness of the two plates as long as the ratio of the thicknesses is maintained within the recited value. In particular a quarter wave net retardance of an incident light beam operating between 3 and 11 microns is provided when the cadmium sulfide plate is 1.25 millimeters and the cadmium selenide plate is 1.0666 millimeters.