Reduction of non-linear effects in optical fiber communication systems and method of using same
AssigneeGeneral Instrument Corporation
InventorDavid R. Huber
Life of this patent
Estimating the term…
Abstract
Non-linear effects in an optical fiber used for communicating AM signals at high power levels are reduced by increasing the linewidth of the pump laser output signal. The linewidth can be increased by optically broadening the laser output signal by driving an optical angle modulator with broadband electrical noise. The optical pump signal is then externally modulated with an AM information signal for transmission over an optical link fiber. The optical modulation can be provided using either an FM or PM optical modulator. A desired linewidth can be provided by controlling the optical modulation index during the optical modulation step and/or by controlling the bandwidth of the noise source.
Claims20
A method for reducing non-linear effects in an optical fiber used for communicating optical signals, comprising the steps of:
- providing a laser output signal having a mode at a frequency .nu..sub.0 ;
- increasing the linewidth of said mode to provide a broadened optical signal generally centered around .nu..sub.0 ;
- externally modulating said broadened optical signal with an information signal;
- and
- coupling the modulated broadened optical signal to an optical link fiber for transmission to a receiver.
Apparatus for communicating optical signals over an optical fiber comprising:
- a light source for providing an optical carrier;
- means for optically modulating said carrier by broadband electrical white noise to provide a broadened optical carrier;
- external modulator means, coupled to receive the broadened optical carrier, for modulating said broadened carrier with an information signal;
- and
- means for coupling the broadened carrier modulated with said information signal from said external modulator means to an optical transmission path.
Apparatus for communicating optical signals over an optical fiber comprising:
- a light source for providing an optical carrier;
- means for optically modulating said carrier by broadband electrical noise to provide a broadened optical carrier;
- external modulator means, coupled to receive the broadened optical carrier, for modulating said broadened carrier with an AM information signal;
- and
- means for coupling the broadened carrier modulated with said information signal from said external modulator means to an optical transmission path.
Dependencies are inferred from the claim text.