To provide a device and method and the like for light wave interference.

An input-side polarization controller 102 of the light wave interference device 101 receives the input of light wave and injects an injection light wave generated by controlling the polarization of the input light wave into a semiconductor laser part 103, which emits a exit light wave on an output-side polarization control part 104 with the injection light wave; and the output-side polarization control part 104 receives the exit light wave and outputs an output light wave generated by controlling the polarization of the exit light wave. Here, one of conditions of 'The polarization direction of the injection light wave that the input-side polarization control part 102 injects does not match with the polarization direction of characteristic mode of the semiconductor laser part 103' and 'When the light wave is not injected into the semiconductor laser part 103, the polarization direction of the output light wave outputted by the output-side polarization control part 104 by the light wave emitted by the semiconductor laser part 103 does not match with the polarization direction of the light wave emitted by the semiconductor laser part in the absence of the output-side polarization control part 104' is met.