Patent ID: 8873898

Claim:
A polarization independent wavelength converter comprising: a polarization maintaining optical fiber that includes a first end and a second end, and has a first polarization axis and a second polarization axis, the first polarization axis and the second polarization axis being orthogonal to each other and propagating light at different velocities; and a group velocity difference cancellation unit that receives a signal light having a certain polarization state and a pump light including a polarization component parallel to the first polarization axis and a polarization component parallel to the second polarization axis and that causes the signal light and a wavelength-converted light to pass through the polarization maintaining optical fiber in a manner not to be influenced by a group velocity difference of each of the signal light and the wavelength-converted light between the first polarization axis and the second polarization axis, the wavelength converted light being light generated in the polarization maintaining optical fiber by propagation of the signal light and the pump light through the polarization maintaining optical fiber.