Subcarrier-multiplexed optical transmission systems using optical channel selection

Abstract From the Canadian patent

Abstract An optical amplifier is used as a frequency-selective high-gain element in a subcarrier-multiplexed fiber optic transmission system. A high-speed diode laser optical transmitter is modulated by a plurality of independent information channels that are carried on separate, appropriately spaced carrier frequencies. An optical receiver, coupled to the transmitter by way of an optical fiber, includes a narrow-bandpass semiconductor laser optical amplifier having a gain bandwidth smaller than wavelength distances between adjacent ones of the carrier frequencies, a photodetector coupled to the output of the amplifier, and polarization controlling means coupled to the fiber in front of the …