An acoustic emission wave detector includes a housing, an optical fiber that guides light from a wideband light source into the housing, and an FBG housed in the housing and having a diffractive grating that reflects light guided into the housing. The FBG is fixed on a side of the other end in the housing such that the light guided into the housing is received by one end thereof. An acoustic emission wave from a high-voltage apparatus is received by the other end thereof.
展开▼