HOLOGRAPHIC OPERATING OPTICAL APPARATUS

A holographic apparatus has an inferometer for concurrently irradiating an image recording medium by a writing reference light of spherical or plane wave form and a signal light containing image information which interfere with each other to form a hologram, and means for irradiating the hologram by a reading reference light in the opposite direction of the reference light to thereby reconstruct the image information. The image recording medium is comprised of a photoconductive layer, an optical reflective layer, a pair of liquid crystal alignment layers, a ferroelectric liquid crystal layer having bistable memory characteristic between its optical reflectivity and an applied voltage, means for applying the voltage and a pair of transparent substrates. The interferometer is preferably of the Mach-Zehnder type which includes along its signal light forming path an optical shutter, means for entering image information and an imagery optical system for optionally optically Fourier transforming the input image information and then enlarging the same to form the image on an otpical writing face of the light addressed liquid crystal light valve. By such construction, an extremely small holographic apparatus can be obtained to record and read the hologram in real time.