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:
Apr. 14, 1992
Filed:
Jan. 03, 1990
Vincent A O'Byrne, Boston, MA (US);
GTE Laboratories Incorporated, Waltham, MA (US);
Abstract
Apparatus for optical transmission of first and second digital channels. Each digital channel has first and second signal levels. The appparatus has a tunable laser for emitting an optical output at optical frequencies corresponding to current levels. Current responsive to the signal levels of the two channels provides current levels to cause the laser to emit a first optical frequency when the first channel has a second signal level and the second channel has a second signal level, a second optical frequency when the first channel has a first signal level and the second channel has a second signal level, a third optical frequency when the first channel has a first signal level and the second channel has a first signal level, and a fourth optical frequency when the first channel has a second signal level and the second channel has a first signal level. An optical transmission medium is coupled to the output of the laser. A tunable optical filter is coupled to the optical transmission medium. The filter is tuned to pass a pair of adjacent optical frequencies corresponding to a signal level on a selected channel. A baseband detector at the output of the optical filter for provides a mark when either of the pair of optical frequencies passes through the optical filter. The mark is indicative of a signal level on the selected channel.