Computation of the cascaded optical fractional Fourier transform under different variable scales

A simple but effective method for calculating the cascading of the multiple stages of optical fractional Fourier transform was proposed. Unlike the previous methods for solving the problems of cascading the optical fractional Fourier transform, we did not change the structures of the optical setups proposed by Lohmann but calculate the cascaded optical fractional Fourier transform with modified transform orders obtained by our method. Computer-simulation and experimental results were presented and a good agreement between them was obtained.