A method of recording a spatially low-frequency heterodyne hologram, including
spatially heterodyne fringes for Fourier analysis, includes: splitting a laser
beam into a reference beam and an object beam; interacting the object beam with
an object; focusing the reference beam and the object beam at a focal plane of
a digital recorder to form a spatially low-frequency heterodyne hologram including
spatially heterodyne fringes for Fourier analysis; digital recording the spatially
low-frequency heterodyne hologram; Fourier transforming axes of the recorded spatially
low-frequency heterodyne hologram including spatially heterodyne fringes in Fourier
space to sit on top of a heterodyne carrier frequency defined by an angle between
the reference beam and the object beam; cutting off signals around an origin; and
performing an inverse Fourier transform.