Optical integrated circuit type interferometer

摘要

PURPOSE:To detect a direction in which the phase of a measuring light changes based on the movement of an object along with higher resolutions, by providing an optical distance cycle changing means to cyclically vary a difference of an optical distance of reference light from that of the measuring light relatively at a fixed amplitude. CONSTITUTION:A thin film substrate 23 of an optical integrated circuit type interferometer 21 has a light waveguide 26 to divide coherent light P from a laser light source 20 into reference light P1 and measuring light P2 so that the measuring light P2 is introduced to a corner cube 24 as object and the reflected light thereof is made to interfere with the reference light P1 to be introduced to a photodetector 25. A pair of electrodes 34 provided sandwiching a reference light waveguide 29 with which the reference light P1 is taken out to be introduced to an incident waveguide 28 functions as optical distance cycle varying means to cyclically vary a difference of an optical distance of the reference light P1 from that of the measuring light P2. This enables detection of a direction in which the phase of the measuring light changes while allowing the removal of a DC bias component, thereby achieving higher resolutions.