Partial elimination of shot noise in optical delayed heterodyne interferometer with incoherent light using spectral interference

We succeeded in reducing the shot noise inherent in the optical delayed heterodyne interferometer with incoherent light by introducing spectral interference. Theoretically, the shot noise level of our interferometer is 1/M of the conventional delayed heterodyne interferometer, where M is the number of wavelength divisions of the spectral interference. In our simulation experiment, the shot noise was reduced 20 dB from the conventional delayed heterodyne interferometer. This technique will reduce the image-acquisition time of optical reflectometry that uses incoherent light.