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:
Jan. 05, 1988
Filed:
Nov. 24, 1986
Applicant:
Inventor:
Liang Tzeng, Fogelsville, PA (US);
Assignee:
American Telephone and Telegraph Company, AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455619 ; 455616 ;
Abstract
A coherent lightwave demodulator is disclosed which is insensitive to the polarization state of the incoming message signal. The demodulator includes a pair of optical hybrids (aligned to the polarization state of the local oscillator) and a pair of optical balanced receivers. A squaring arrangement, for example a delay demodulator, responsive to the output from the pair of optical balanced receivers eliminates the polarization-dependent component of the message signal and allows the recovery of the message signal regardless of the polarization state of the incoming message signal.