In a image processing using a Fourier spectrum, phase information usually has a more important role than the amplitude information. In this thesis, The properties of phase-only filters(POF) and binary phase-only filters(BPOF) to be placed in the spatial frequency plane of the optical correlator is investigated and the real time spatial light modulators suitable for encoding the phase-only filters are examined. A method of optimal encoding of POFs by using the gradient descent iteration algorithm is described. The method is applied discriminating multiple objects, both results of computer simulations and optical experiments show that the proposed method is superior to the conventional encoding method of POFs, for the respects of light efficiency and signal to noise ratio, also it has resulted out good discrimination properties. Measurement of the light, modulated by the liquid-crystal television spatial light modulator(LCTV-SLM), in terms of polarization states by using Stokes parameters and the phase retardation properties by using a Mach-Zehnder interferometer has been done. Base on the measured results, the binary phase modulation condition is solved analytically, and it is implemented using a quarter-wave plate and a analyzer. A phase correction method is described for the compensation of the phase nonuniformity which is arising form the thickness nonuniformity of the commercially available-LCTV-SLM. The results of computer simulation show that the method is efficient for reducing the phase nonuniformity in case of LCTV-SLMs displaying the BPOF. The temporal behaviors of the photoinduced anisotropy in amorphous $As_2S_3$ thin film, under the illumination of linearly polarized Ar-ion laser light, is investigated in terms of 3rd order nonlinear optical susceptibilities. Using the property of photoinduced anisotropy, the principle of binary amplitude modulation and binary phase modulation of the reading beam is described. Especially, the binary phase modulation property of the photoinduced anisotropic medium is applied to recording the binary phase-only filters in a Vander Lugt optical correlator, and by observing the time sequencial change of the correlation peaks, we convinced that the amorphous $As_2S_3$ thin film can be used for the rewritable real time spatial light modulator for recording the spatial filter informations in a Vander Lugt optical correlater.
