Holographic optical elements recorded in silver halide sensitized gelatin emulsions. Part I. Transmission holographic optical elements

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holo graphic optical elements (HOE's). The drawback of DCG is its low sensitivit y and limited spectral response. Silver halide materials can be processed i n such a way that the final hologram will have properties like a DCG hologr am. Recently this technique has become more interesting since the introduct ion of new ultra-high-resolution silver halide emulsions. An optimized proc essing technique for transmission ROE's recorded in these materials is intr oduced. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardeni ng process has made it possible to obtain results similar to conventional D CG processing. The main advantage of the SHSG process is that high-sensitiv ity recording can be performed with laser wavelengths anywhere within the v isible spectrum. This simplifies the manufacturing of high-quality, large-f ormat HOE's. (C) 2001 Optical Society of America OCIS codes: 090.2890, 090. 2900, 230.1950, 040.5190, 350.5130.