Fabrication of holographic binary phase Fresnel lens arrays using inorganic photoresist

The simple two-step method of binary phase microlens holographic recording, using As40Se60 inorganic resist ( thermally evaporated As40Se60 layers) is presented. First step is fabrication of a master binary zone plate. During the recording of the holographic lens arrays this master lens was illuminated by the collimated argon laser irradiation and the interference pattern resulting from the interference of zeroth-and first-orders of diffraction was recorded in the As40Se60 layer. The contribution of the higher orders of diffraction was similar to two orders smaller. During the postexposure treatment the formed image was transferred into the glass substrate. The 8x12 planar holographic lens array was formed in glass plate. Each lens unit in array has 3.5 mm diameter, with focal length 37.5 mm and number of zones similar to 200. The zone profile of each lens unit is rectangular, and diffraction efficiency is similar to 33 %.