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:
May. 11, 1982
Filed:
Mar. 03, 1980
Charles R Pond, Federal Way, WA (US);
Patrick D Texeira, Renton, WA (US);
Reynold E Wilbert, Seattle, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A filter and beam combiner is comprised of a small glass plate having a microscopic two sided elliptical mirror on one side thereof. The signal beam is spatially filtered on one side of the mirror and then directed to a target. On the other side of the mirror there is a compensating glass plate through which the reference beam passes, to correct for refraction relative to its passing through the first plate, before it enters the other glass plate and is directed onto said other side. The reference beam is spatially filtered by the mirror for combination with the signal beam, which returns from the target substantially enlarged by diffraction so as to pass around the mirror and through the plate to be combined with the reference beam. The signal beam is passed through acousto-optic modulator (AOM). The reference beam is passed through an 81 MHz AOM. The AOM's produce a doppler shift of the coherent light source frequency as the light is diffracted by a moving sound wave in the modulator. When the two beams are combined, the fringe position is proportional to the phase of the 1 MHz frequency modulation difference frequency. The signal beam and the reference beam are combined as the former passes around the mirror and the latter is reflected thereby, forming a composite beam to form interference patterns, and from which can be extracted, with extremely high resolution, information concerning the physical characteristics of the target.