Real time Joint Transform Correlator using phase conjugation in photorefractive crystal

This paper presents a technique for realising the Joint Transform Correlator (JTC) in real time using a Barium Titanate crystal and a low power He-Ne laser. This technique avoids the use of additional CCD camera and electrically addressed SLM, and provide high fidelity correlation peak. The phenomenon of Degenerate Four Wave Mixing (DFWM) is used for image correlation in this experiment. The object and reference are arranged in a single beam and the Joint Fourier Transform is focussed in the crystal. Fourier Transform (FT) of the conjugate beam gives the required correlation. The peaks are recorded with the help of low light sensitive CCD camera for further analysis for determining the exact location of the target.