افزايش بازدهي پراش توري بازتابي هولوگرافيك با خشك كردن درخلا

The main recording material for recording holographic optical elements (HOE) is dichromated gelatin (DCG.) The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide sensitized gelatin (SHSG) technique has become more interesting since the introduction of new ultra-fine-grain silver halide (AgHal) Emulsions. In this technique Silver halide materials can be processed in such a way that the final hologram has properties like a DCG hologram. In particular, high spatial-frequency fringes associated with HOE of reflection type are difficult to construct when SHSG processing methods are employed. The main advantage of SHSG technique is that high-sensitivity recording can be performed with laser beam anywhere within the visible spectrum. Therefore an optimized processing technique for reflection HOE recorded in the new AgHal materials is introduced and Finally with drying in vacuum oven, diffraction efficiency of more than 50% is obtained for reflection gratings of 5120 lines.mm-1.