Wavelength cross connect device, and wavelength cross connect method

A wavelength cross-connect device comprising:

• an input-side wavelength selective switch (WSS) configured to receive a wavelength-multiplexed optical signal from one or more input paths and to separate the wavelength-multiplexed optical signal into one or more optical signals in accordance with respective output paths;
• an output-side WSS configured to multiplex the one or more separated optical signals and to output a wavelength-multiplexed optical signal to one or more output paths;
• and
• a wavelength band switching unit disposed between the input-side WSS and the output-side WSS and configured to switch a wavelength band of the optical signals in accordance with a selected output path,
• wherein the wavelength band switching unit includes:
• a first WSS configured to receive one or more optical signals output from the input-side WSS and to select one or more of the optical signals;
• one or more wavelength band converters configured to convert a wavelength band of the optical signals selected by the first WSS into a different wavelength band;
• and
• a second WSS configured to output the optical signals after wavelength band conversion to the output-side WSS.

A wavelength cross connect method comprising:

• receiving a wavelength-multiplexed optical signal from one or more input paths;
• separating, by an input-side wavelength selective switch (WSS), the wavelength-multiplexed optical signal into one or more optical signals in accordance with respective output paths;
• supplying one or more optical signals not requiring wavelength band conversion directly to an output-side WSS;
• supplying one or more optical signals requiring wavelength band conversion to a wavelength band switching unit;
• selecting, by a first WSS of the wavelength band switching unit, one or more optical signals;
• converting, by one or more wavelength band converters, a wavelength band of the selected optical signals to different wavelength band;
• and
• outputting, by a second WSS of the wavelength band switching unit, the optical signals after wavelength band conversion to the output-side WSS.