Patent ID: 8798463

Claim:
An optical channel monitor, comprising: a polarization adjuster configured to adjust, of a first optical signal and a second optical signal that are multiple wavelength light, a direction of a plane of polarization of the first optical signal to a first direction and a direction of a plane of polarization of the second optical signal to a second direction that is orthogonal to the first direction; a polarization multiplexing signal generator configured to perform polarization multiplexing onto the first optical signal and the second optical signal each having the direction of the plane of polarization adjusted by the polarization adjuster to generate a polarization multiplexing signal that includes the first optical signal and the second optical signal; a wavelength divider configured to divide each of optical signals that are multiplexed on the first optical signal and the second optical signal that are included in the polarization multiplexing signal, in accordance with wavelengths; a polarization divider configured to divide each of the optical signals divided by the wavelength divider in accordance with the wavelengths, based on the direction of the plane of polarization; a first intensity detector configured to receive an optical signal whose direction of the plane of polarization is the first direction from among the optical signals divided by the polarization divider, and detect an intensity of the first optical signal in accordance with the wavelengths; and a second intensity detector configured to receive an optical signal whose direction of the plane of polarization is the second direction from among the optical signals divided by the polarization divider and detect an intensity of the second optical signal in accordance with the wavelengths.