Diffraction properties of double-layer rectangular phase gratings

Abstract

Abstrac t.We theoretically present di raction properties of double-layer rectangular phase gratings (DLRPGs). Computer simulations show that these DLRPGs can realize several functions such as optical ® ltering, optical switching, optical amplitude modulating, beam splitting with variable output beam numbers and wavelength division multiplexing, and so on. As a test of the above di raction properties, we fabricate a set of DLRPGs in a double-layer lightsensitive material by the contact printing method. Based on the DLRPGs of the material, a single beam splitter with experimental results of splitting of an incident beam into 2, 3 or 5 output beams and of higher than 64% total di raction e ciency are realized when the incident angle of the readout beam is tuned during the reading process. Journal of Modern Optics ISSN 0950± 0340 print/I SSN 1362± 3044 online # 2000 T aylor & Francis Ltd