Abstract: “Increasing demand of high speed in data and image processing; optical computing has been proved its inevitability through its inherent properties. Different logic gates are the essential part of the processing unit. Semiconductor optical amplifier properties have created a new interest in the field of construction of the all optical logic gates with various encoding techniques. Phase encoding drew more attention to the researchers as it shows extended tolerance limit in long-haul fiber transmission system with higher receiver sensitivity. Thus phase encoding gives high spectral efficiency in optical computing and communication both. Four wave mixing (FWM) in semiconductor optical amplifier (SOA) is an intra band non linear process so it requires very short switching time. Thus phase encoding with FWM in SOA for the construction of the all optical logic processor gives very high-speed operation. Some optical logic gates already proposed and demonstrated experimentally by some research g”

Keywords: SOA, FWM, CMZI, NAND, Phase modulator, Phase shifter and Optical logic gate.