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. 07, 2014
Filed:
Jul. 06, 2011
Hideharu Mikami, Kawasaki, JP;
Hideharu Mikami, Kawasaki, JP;
Oclaro Japan, Inc., Kanagawa, JP;
Abstract
In a free space optical system type demodulator of a phase shift keying signal, if a half beam splitter is used as a non-polarizing optical branching unit that is used when generating beams corresponding to I and Q channels or when multiplexing an interference light, control of a power branching ratio is difficult, and it is necessary to suppress phase shifts that are different depending on a polarization state of an input state, and thereby the demodulator becomes high cost. Moreover, since directions of branched lights are different, it is difficult to suppress a skew of the demodulator. In the present invention, the non-polarizing optical branching unit that is used when generating the beams corresponding to the I and Q channels and when multiplexing the interference light is realized using polarization rotating elements and polarization separating elements. Moreover, branched beams are substantially aligned.