Real-time heterodyne imaging interferometry using three-phase correlation image sensor

We propose real-time heterodyne imaging interferometry using the three-phase correlation image sensor (3PCIS). The 3PCIS produces temporal correlation between incident light intensity and three-phase reference signals at each pixel and outputs the results as images in every frame. This property enables simultaneous demodulation of amplitude and phase images of heterodyne interference within a single frame. We developed a real-time imaging system of heterodyne interferometry based on a Michelson polarization interferometer using a 3PCIS and a two-frequency He-Ne laser with a beat frequency of 25 kHz. We confirmed by experiments that a video sequence of demodulated amplitude and phase images of heterodyne interference was successfully obtained under a frame rate of 122 frames/s.