Continuous phase-shifting holography

A scanning full-field interferometer is a key devise in the optical scheme of digital hyperspectral hologram registration. Behind the theory of hyperspectral holography is Fourier transform spectroscopy wherein the set of spectrally resolved complex amplitudes of the object’s hyperspectral field is obtained via the Fourier transform of a series of interferograms registered in incoherent radiation. Several established approaches in digital holography, based on discrete phase-shifting techniques as well as continuous phase modulation of the reference signal by a scanning mirror, are special cases of Fourier transform spectroscopy, where a coherent light source is used for hologram registration. The proposed algorithm was found to apply to processing holograms registered by various phase shifting techniques and can give a greater signal to noise ratio.