Abstract: The Fractional Fourier Transform (FRFT.) is the generalization of the classical Fourier Transform and was introduced many years ago in mathematics literature. The original purpose of FrFT is to solve the differential equation in quantum mechanics problems in optics . Most of the applications of FrFT in optics . It depends on a parameterα and can be interpretedas rotation by an angle α in the time frequency plane or decomposition of the signal in terms of chirps. It is also used in digital domain. Because of its simple and of beautiful properties in time – frequency plane, there are many new applications waiting for signal processing.