Patent · US Expired

Optical frequency modulation system

US4561119A · kind A · utility

85Cited by
3References
12Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 23, 1982
Grant dateDec 24, 1985
Priority date
Expiry dateAug 23, 2002

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B14/006
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An optical communication system including at a transmitter a semiconductor laser (2) and at a receiver a photodetector (3). Intermediate the transmitter and the receiver is an optical frequency discrimination (4), e.g. a Fabry-Perot resonator. The laser (2) is operated at a substantially constant average power level above the lasing threshold. Superimposed (5) on the substantially constant bias current is a low level modulation signal. The level of modulation of the bias current is sufficient only to cause an effective change in the optical frequency of the laser output without causing the laser oscillations to change from one longitudinal mode to another. The discriminator (4) is tuned to one of the frequencies thus produced.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.