Optical signal relay apparatus, optical transmission system, and optical signal relay method

An optical transmission system comprising an optical signal relay apparatus and a storage device configured to store information relating to a distortion being generated at a time of wavelength conversion, wherein

• the optical signal relay apparatus includes
• an input unit including a first input terminal to which a first optical signal including at least one wavelength is input via a first transmission line, and a second input terminal to which a second optical signal including at least one wavelength is input via a second transmission line,
• a wavelength selective switch unit configured to, when a same-wavelength optical signal having the same wavelength as a wavelength included in the second optical signal is present in a wavelength included in the first optical signal, separate the same-wavelength optical signal,
• a wavelength conversion unit configured to convert the wavelength of the same-wavelength optical signal into a different wavelength,
• an optical compensation unit configured to compensate for a predetermined distortion being generated when converting the wavelength of the same-wavelength optical signal into the different wavelength,
• a control unit configured to acquire the predetermined distortion, based on a database that stores in advance a relationship among the wavelength conversion, a distortion being generated at a time of the wavelength conversion, and a transmission rate of an optical signal, the wavelength of the same-wavelength optical signal, the different wavelength, and the transmission rate of the same-wavelength optical signal, and control the optical compensation unit in such a way as to compensate for the predetermined distortion, and
• an output unit configured to output a different-wavelength optical signal including the different wavelength after the predetermined distortion is compensated, and
• the storage device stores, in the database in advance, a relationship among the wavelength conversion, a distortion being generated at a time of the wavelength conversion, and the transmission rate of an optical signal.

An optical signal relay method comprising:

• separating, when a same-wavelength optical signal having the same wavelength as a wavelength included in a second optical signal including at least one wavelength is present in a wavelength included in a first optical signal including at least one wavelength, the same-wavelength optical signal;
• converting a wavelength of the same-wavelength optical signal into a different wavelength;
• compensating for a predetermined distortion being generated when converting the wavelength of the same-wavelength optical signal into the different wavelength;
• acquiring the predetermined distortion, based on a database that stores in advance a relationship among the wavelength conversion, a distortion being generated at a time of the wavelength conversion, and a transmission rate of an optical signal, the wavelength of the same-wavelength optical signal, the different wavelength, and the transmission rate of the same-wavelength optical signal, and performing control in such a way as to compensate for the predetermined distortion;
• and
• outputting a different-wavelength optical signal including the different wavelength after the predetermined distortion is compensated.