DIFFRACTIVE-PHASE-ELEMENT DESIGN THAT IMPLEMENTS SEVERAL OPTICAL FUNCTIONS

A scheme for the design of diffractive phase elements (DPE's) that int egrates several optical functions is presented in a consistent sense b ased on the general theory of amplitude-phase retrieval and the Yang-G u algorithm [Appl. Opt. 33, 209 (1994)]. We extend the original Yang-G u algorithm to treat a system illuminated by a beam of incident light whose components are at different wavelengths, and a set of equations for determining the phase distribution of the DPE is derived. The prof ile of a surface-relief DPE can be designed with an iterative algorith m. Numerical simulations are carried out for the design of one-dimensi onal DPE's capable of both demultiplexing different wavelength compone nts and focusing each partial wave at predetermined positions. The inf luence of the extension of sampling points in the DPE's from ideal geo metric points to physical spots on design results is also investigated . The numerical simulation results show that the new algorithm can be used successfully to design the desired DPE's. It is therefore expecte d to be useful in the design of DPE's for micro-optical systems.