Patent ID: 6151159
Filing Date: 2000-11-21
Classification: H01S,H04B,H04J

Abstract:
An optical amplifier for wavelength multiplex transmission, comprising:an optical fiber for amplifying input optical signals of wavelengths .lambda.1.about..lambda.n which are wavelength multiplexed, where n is an integer greater than 0;a pumping light source for generating pumping lights to excite said optical fiber for amplification;a wavelength optical multiplexer for inserting said pumping lights to said optical fiber for amplification;an optical coupler for branching the amplified optical signals by said optical fiber for amplification;a wavelength separator for separating both amplified spontaneous emission light which is generated spontaneously by said optical fiber for amplification and signal lights of signal wavelength from said branched optical signals;a photo receiver for detecting the strength of said amplified spontaneous emission light;a photo detector for detecting the strength of said signal lights; anda strength level comparator/pumping light source controller which controls the output of the pumping light source to have the output level of said optical signals set arbitrarily, based on the strength detected by said photo detector,the optical amplifier for wavelength multiplex transmission being capable of controlling the output level of said pumping light source, by said strength level comparator/pumping light source controller so as to have an amplification factor with a suitable gain flatness.