Patent ID: 6078414
Filing Date: 2000-06-20
Classification: H04B

Abstract:
A circuit comprising:a plurality of optical transmitters each comprising:(i) a laser light source which produces a light wave of a different wavelength;(ii) an optical modulator which modulates the light wave according to input data to produce an optical signal; and(iii) a frequency-modulation driver which drives the laser light source in predetermined frequency modulation;an optical coupler which combines optical signals received from the optical transmitters to produce optical wavelength-division multiplexing (WDM) signals;an optical amplifier which amplifies the optical WDM signals for transmission onto an optical fiber;a detector which sequentially detects back-propagating waves caused by respective ones of the optical WDM signals from the optical fiber to produce a plurality of corresponding detection signals, the back-propagating waves propagating in a direction opposite to the optical WDM signals; anda controller which sequentially controls the frequency-modulation drivers of said plurality of optical transmitters to vary a degree of frequency modulation performed by the frequency-modulation drivers depending on respective ones of said detection signals.