A repeated FFT algorithm method is devised and calculation of the field distribution across a plane situated close to and far from the focal plane becomes possible. This overcomes the shortcomings of the fast Fourier transform (FFT) algorithm by which a substantial reduction of the computation time for the field distribution of focused light can be achieved only for the local field distribution adjacent to the focal plane.
© 1988 Optical Society of America
Seiji Nishiwaki, "Calculations of optical field by fast Fourier transform analysis," Appl. Opt. 27, 3518-3521 (1988)