Phase-shifting Digital Holography

As a compound of computer technology and optical holography, digital holographytechnology is one of the fastest growing branch of information optics. With combination ofdigital holography technology and optical holography, high precision measurement ispossible by recording hologram pictures, which could be widely used in defence of civilscientific research and other fields.Accurate phase-shifting is closely connected with holographic reappearance inphase-shifting digital holography technology which is a key technology. We have done thefollowing several work in order to solve this issue:(1)Sinusoidal grating, made by computer image technology, is entered the liquid crystalspatial light modulator. Then, by translating sinusoidal grating, reference light wave willproduce a phase, which ensures the precision and stability of the light wave phasemodulation.(2)Phase-shifting digital holographic recording optical path system is established. Byjoining the spatial light modulator in the reference light path, let light waves go through thenspatial light filtering system, we get the reference light wave, which could realize phasemodulation.(3)We continuously record hologram pictures of different time through two specificphase hologram. A computer analysis program is established to pick two phase shifthologram with a certain phase difference, used for hologram reappearance.(4)Phase-shift digital hologram of two-dimensional transmission objects is recorded.And we realize the reappearance of hologram through computer programs, and draw asatisfactory reappearance hologram picture.