Patent ID: 6707963
Filing Date: 2004-03-16
Classification: H04B,H04J

Abstract:
A wavelength division multiplexing apparatus comprising:a plurality of variable attenuators to which a plurality of optical signals of different wavelengths are respectively input, and which respectively attenuate the input optical signals with variable amounts of attenuation; an optical combiner which combines optical outputs of the plurality of variable attenuators; an optical amplifier which optically amplifies an optical output of the optical combiner; a spectrum analyzer unit which measures the spectrum of an optical output of the optical amplifier, and controls each of the plurality of variable attenuators so as to maintain the optical power level of each wavelength at a predetermined level in accordance with the result of the measurement; means for externally setting a wavelength not used among the plurality of optical signals; optical shutoff means for shutting off an input of an optical signal of a the wavelength not used among the plurality of optical signals.