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:
Dec. 07, 2010
Filed:
Jan. 09, 2007
Xinghua Wang, Pittsburgh, PA (US);
Xinghua Wang, Pittsburgh, PA (US);
ChemImage Corporation, Pittsburgh, PA (US);
Abstract
A spectral filter is adapted for use in a receiver, for example in a short range submarine laser signal path, wherein the relative orientations of the receiver is such that the signal may appear diffusely or at an unknown point in a wide external field of view around an optical axis of the receiver. A narrow band spectral filter in the receiver has cascaded stages of tunable retarders with includes multi-conjugate stages that tolerate light that is oblique to normal, up to a diverging internal field of view angle up to about 10°. A fisheye lens assembly refracts incoming light from a wider external field of 170° or more and directs the light into the filter over the narrow internal field of view. Calibration and feedback control can be provided to stabilize the discriminated wavelength peak, which remains at the same center wavelength over the span of the internal field of view notwithstanding the difference in retarder thicknesses traversed along paths that are normal to the retarders versus oblique to the optical axis.