Wavelength cross connect device and wavelength cross connect method

A wavelength cross-connect device,

• wherein the wavelength cross-connect device performs relay processing, the relay processing being such that wavelength multiplexed signal lights, in which optical signals of a plurality of different wavelength bands are multiplexed and which are multiband transmitted via an optical transmission line configured by one or a plurality of optical fibers, are demultiplexed into different wavelength bands, and for each route, respective optical signals of the different wavelength bands are amplified, then subject to rout change by WSSs (Wavelength Selective Switches) and outputted to output side routes;
• the wavelength cross-connect device
• includes WXC (Wavelength Cross Connect) units that are the same in total number as the wavelength bands of the optical signals of respective wavelength bands, have optical amplifiers and the WSSs, and perform the relay processing on the optical signals of a predetermined specific wavelength band of the different wavelength bands;
• includes input side conversion units provided on the input side of the WXC units for converting optical signals of wavelength bands other than the specific wavelength band into optical signals of the specific wavelength band;
• includes output side conversion units provided on the output side of the WXC units for converting the optical signals of the specific wavelength band converted by the input side conversion units into before-conversion optical signals;
• and
• the optical signals of the specific wavelength band directly input from the input side are directly output after the relay processing by the WXC units.