POLARIZATION SWITCHING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a polarization switching circuit capable of selecting between a state of performing polarization rotation and a state of not performing the polarization rotation.SOLUTION: A polarization switching circuit includes: a first polarization conversion circuit 10 for outputting mode light adjusted according to the mode light of two different polarizations; a mode switching circuit 11 for outputting the mode light as it is or and outputting the mode light inverted when the output of the first polarization conversion circuit 10 is the mode light of a predetermined set polarization; and a second polarization conversion circuit 12 for outputting the mode light adjusted according to the output of a mode conversion circuit 11.SELECTED DRAWING: Figure 3