Wavelength converter, wavelength conversion method, and transmission device

A wavelength converter comprising:

• a first light source configured to generate first pump light;
• a second light source configured to generate second pump light having the same wavelength as the first pump light;
• a polarization combiner configured to polarization-combine the first pump light and the second pump light such that the first pump light is orthogonal to the second pump light;
• and
• a nonlinear medium configured to wavelength-convert inputted first signal light into second signal light having a wavelength band that is different from a wavelength band of the first signal light by using the polarization-combined first pump light and second pump light.

A wavelength conversion method comprising:

• generating first pump light;
• generating second pump light having the same wavelength as a wavelength of the first pump light;
• polarization-combining the first pump light and the second pump light such that the first pump light is orthogonal to the second pump light;
• wavelength-converting first signal light inputted from a first port into second signal light having a wavelength band that is different from a wavelength band of the first signal light in a nonlinear medium by using the polarization-combined first pump light and second pump light to output the second signal light after wavelength conversion from a second port, and wavelength-converting the second signal light inputted from the second port into first signal light in the nonlinear medium by using the polarization-combined first pump light and second pump light to output the first signal light after wavelength conversion from the first port;
• inputting the first signal light from the first port into the nonlinear medium, and outputting the first signal light after wavelength conversion in the nonlinear medium from the first port;
• and
• inputting the second signal light from the second port into the nonlinear medium, and outputting the second signal light after wavelength conversion in the nonlinear medium from the second port.

A transmission device comprising:

• a wavelength converter configured to wavelength-convert first multiplexed light into second multiplexed light having a wavelength band that is different from a wavelength band of the first multiplexed light, and wavelength-convert the second multiplexed light into the first multiplexed light, wherein
• the wavelength converter includes:
• a first light source configured to generate first pump light;
• a second light source configured to generate second pump light having the same wavelength as the first pump light;
• a polarization combiner configured to polarization-combine the first pump light and the second pump light such that the first pump light is orthogonal to the second pump light;
• and
• a nonlinear medium configured to wavelength-convert the first multiplexed light inputted from a first port into the second multiplexed light by using the polarization-combined first pump light and second pump light to output the second multiplexed light after wavelength conversion from a second port, and wavelength-convert the second multiplexed light inputted from the second port into the first multiplexed light by using the polarization-combined first pump light and second pump light to output the first multiplexed light after wavelength conversion from the first port;
• a first circulator configured to input the first multiplexed light from the first port into the nonlinear medium, and output the first multiplexed light after wavelength conversion in the nonlinear medium from the first port;
• and
• a second circulator configured to input the second multiplexed light from the second port into the nonlinear medium, and output the second multiplexed light after wavelength conversion in the nonlinear medium from the second port.