OPTICAL TRANSMITTER

摘要

PURPOSE: To minimize the deterioration in the CNR and to realize multi- distribution of light without deterioration in distortion in the case of optical fiber amplifiers connected in cascade. CONSTITUTION: An optical signal outputted from an electrooptic control section 101 is amplified and distributed by optical fiber amplifiers 103, 106 connected by 2 stages in cascade and an optical demultiplexer 104 inserted between both the optical fiber amplifiers. The components above are arranged all in a wired broadcast station so as to allow a short transmission distance between the optical fiber amplifiers. A low noise forward stimulation optical fiber amplifier is adopted for the optical fiber amplifier 103 at the 1st stage and a backward stimulation optical fiber amplifier is adopted only for the final stage amplifier 106 connected directly to the optical transmission line and requiring an inter- transmission reception level difference. An input optical signal power to each optical fiber amplifier is selected to be a prescribed power so that the wavelength of the optical signal and the gain peak wavelength of each optical fiber amplifier are made coincident.