Patent attributes
A light path circuit apparatus suited for a small sized ring laser gyro, includes a base having a standard plane, one or more substrates laminated parallel against the standard plane in a direction orthogonal to the standard plane, a light source, wherein on the base and/or the one or more substrates, 3 or more reflective surfaces, having normal lines within a prescribed one plane orthogonal to the standard plane, are constituted parallel or with tilt by a prescribed angle to the standard plane, the light source is disposed to emit light within the prescribed one plane, and the light emitted from the light source circulates within the one plane in a forward and backward direction by three or more reflective surfaces and constitutes a light path circuit that laser oscillates.