Volume transmission gratings in dichromated gelatin for near infra red applications

It is possible to increase the dispersion of a volume transmission grating by using a double pass through the device. The extension of this technology to achieve integrated devices is discussed. The importance of the control of the dichromated gelatin film parameters, in order to achieve high efficiency and polarisation insensitivity, is outlined. Preliminary results for 1050 l/mm gratings are presented.<
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