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:
Feb. 15, 1994
Filed:
May. 28, 1992
Applicant:
Inventors:
Richard E Epworth, Sawbridgeworth, GB;
Peter J Anslow, Bishop's Stortford, GB;
Assignee:
Northern Telecom Europe Limited, Montreal, CA;
Primary Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 26 ; 372 31 ;
Abstract
An injection laser driver regulates the bias and modulation depth by means of two feedback control loops, one deriving its feedback control signal from a measure of the mean optical output of the laser, and the other deriving its feedback control signal from a measure of the spectral purity of that optical output. The spectral purity measure is conveniently effected by measuring the coherence function at a specific value of differential delay using a Mach-Zehnder interferometer configuration with a passive quadrature optical network.