Coherent lightwave transmitters

US4755016A · kind A · utility

Assignee

• American Telephone and Telegraph Company, AT&T Bell Laboratories · US

Inventors

• Bernard C. DeLoach, Jr. · New Providence, US
• Richard G. Smith · Orlando, US

Key dates

• Filing date: Nov 6, 1985
• Grant date: Jul 5, 1988
• Expiry date: Nov 6, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S372/703
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A coherent lightwave transmitter includes a relatively low power, single frequency laser which provides an injection locking signal to a plurality of higher power lasers located in separate, parallel optical paths. A modulator is interposed between the single frequency laser and the higher power lasers, and the outputs of the latter are added constructively to form a high power transmitter output. Feedback control of the optical path lengths to maintain constructive interference is also described.