Abstract: An optical transmission unit (3) transmits an optical signal having a light intensity set as a Low level component of a pulse. An optical partial reflector (6) is provided on a path through which transmission light is transmitted from a circulator (5) to the atmosphere, and reflects the optical signal. A detection unit (11) performs coherent detection on reception light using, as local light, a signal in a Low level section in the optical signal reflected by the optical partial reflector (6).

Abstract: In order to provide an induction heating cooking device in which a supporting configuration of a heating coil unit is simple and can be easily assembled, and which can accurately and constantly maintain a distance between a top plate and heating coils, opposite side surfaces of a framework laid out below the top plate are configured to have first vertical parts, first horizontal parts, and second vertical parts. A heating coil supporting member that supports the heating coils is disposed to be bridged between the first horizontal parts of the opposite side surfaces of the framework, and the heating coil unit having the heating coil is configured to be securely supported by the first horizontal parts.

Abstract: In order to provide an induction heating cooking device in which a supporting configuration of a heating coil unit is simple and can be easily assembled, and which can accurately and constantly maintain a distance between a top plate and heating coils, opposite side surfaces of a framework laid out below the top plate are configured to have first vertical parts, first horizontal parts, and second vertical parts. A heating coil supporting member that supports the heating coils is disposed to be bridged between the first horizontal parts of the opposite side surfaces of the framework, and the heating coil unit having the heating coil is configured to be securely supported by the first horizontal parts.