PDL compensator optical device, and PDL compensation method

摘要

A PDL compensation technique is provided that reduces the number of and the number of types of the PDL compensators even if it is uncertain to determine which of the two polarization principal axes of an optical device has a larger loss. The PDL compensator according to the present invention is configured to, before an optical signal input from a first or a second input/output terminal enters a PDL compensation device, switch between the first polarization principal axis and the second polarization principal axis of the optical signal depending on which of the first and the second polarization principal axes has a larger loss or gain.

主权项

1. A polarization dependent loss (PDL) compensator comprising:
first and second input/output terminals configured to input and output optical signals; a PDL compensation device configured to create a loss or gain difference between a first polarization principal axis and a second polarization principal axis of an optical signal input from the first or second input/output terminal; a polarization switch unit configured to, before the optical signal input from the first or second input/output terminal enters the PDL compensation device, switch between the first polarization principal axis and the second polarization principal axis of the optical signal depending on which of the first polarization principal axis and the second polarization principal axis has a larger loss or gain; a first polarization maintaining optical waveguide connecting the first input/output terminal and an input end of a polarization connector portion, while maintaining the state of polarization of an optical signal propagating therethrough; and a second polarization maintaining optical waveguide connecting an output end of the polarization connector portion and an end of the PDL compensation device, while maintaining the state of polarization of an optical signal propagating therethrough, wherein the polarization switch unit is configured to function as a polarization switch that changes the state of polarization of the optical signal input from the first input/output terminal.