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:
Sep. 26, 2000
Filed:
Mar. 04, 1998
Qian Gong, Columbia, MD (US);
Swales Aerospace, Inc., Beltsville, MD (US);
Abstract
The present invention uses a light-pipe for beam splitting, combining, hybrid space-wavelength multiplexing, hybrid space-wavelength demultiplexing, dense wavelength division multiplexing, and dense wavelength division demultiplexing. A light-pipe has a first end where light enters the light-pipe and a second end where the light exits the light-pipe. The light-pipe is a polygonal rod or a hollow reflective cavity. To perform beam splitting, light enters the first end of the light-pipe and reflects off of the side surfaces inside the light-pipe producing additional light beams. By placing an imaging lens at the output end of the light-pipe, all of the virtual images (n-1) of the additional light beams and the original light entering the light-pipe become the object of the imaging lens. As a result, the light-pipe acts as a 1-to-n splitter. If the input signal, that is, the light entering the light-pipe, has more than one wavelength and a grating is added to the second end of the light-pipe, the device becomes a hybrid space-wavelength division multiplexer/demultiplexer. If the spacing between adjacent wavelengths is small, the light-pipe becomes a Dense Wavelength Division Demultiplexer. If the input and output are reversed, the beam splitter becomes a combiner. If the inputs have different wavelengths, the light-pipe becomes a Wavelength Division Multiplexer.