Optical filter, manufacturing method thereof, and optical amplifier equipped with said optical filter

摘要

A method of manufacturing an optical filter that can restrain the wavelength dependence of the gain of an optical amplifier. The input signal light power, output power of pump light source (8), and the output signal light power of an optical amplifier (4) are set to the power values used for optical communication systems, and the total power of the simulation input light of a plurality of wavelengths (lambd1, lambd2, . . . lambdn) from light sources (1a) and an input light (probe light) from light sources (1m) are set equal to the total power of the input signals of a plurality of wavelengths used in wavelength division multiplex transmission systems. In this condition, the input light are multiplexed and are launched into optical amplifier (4), and the amount of attenuation is variably adjusted so that the output power from optical amplifier (4) in correspondence to the probe light will be within the range determined by the maximum and minimum of the output power corresponding to the simulation input light to determine the attenuation amount corresponding to the wavelength of the probe light. The above operation is repeated upon varying the wavelength of the probe light, and loss spectrum of the optical filter is set to the loss spectrum of the attenuation amounts in one-to-one correspondence with the respective wavelengths.