Patent ID: 6055093
Filing Date: 2000-04-25
Classification: H04B

Abstract:
An optical amplifying apparatus, comprising:at least two optical signal transmitter means for respectively transmitting therefrom optical signals having mutually different wavelengths;wavelength multiplexing transmitter means for wavelength multiplexing the optical signals to transmit therefrom a wavelength multiplexed optical signal;optical amplifier means for directly amplifying the multiplexed optical signal and outputting therefrom an amplified multiplexed optical signal;optical signal counting detector means for branching the optical signal into component signals thereof and detecting the number of optical signals currently being transmitted in the multiplexed optical signal; andoptical amplifier control means for controlling an output from the optical amplifier means according to the number of optical signals, wherein:the optical amplifier means includes a fiber made of material to which a rare earth element is added, an excitation light source for outputting therefrom an excitation light, andan optical mixer for inputting the multiplexed optical signal and the excitation signal to the fiber and the optical amplifier control means includes an excitation light control circuit for controlling an intensity of the excitation light according to the number of optical signals anda linear relay optical amplifying apparatus connected via an optical path to the optical amplifying apparatus, whereinthe optical amplifying apparatus includes control signal transmitter means for transmitting a control signal including the number of optical signals and the linear relay optical amplifying apparatus includes relay optical amplifier means for directly amplifying the multiplexed optical signal and for outputting therefrom an amplified multiplexed optical signal and relay optical amplifier control means for controlling an output from the relay optical amplifier means according to the control signal.