Electron-Beam Fabricated Computer-Generated Holograms (GGH) For Aberration Correction Of Holographic Optical Elements (HOE)

Holographic optical elements (HOE) are of interest as focussing or collimating lenses with monochromatic sources because they are very light and compact. HOEs used with sources in the infrared (e.g. laser diodes) have to be fabricated at a wavelength which is different from the application wavelength, since there are no holographic materials available for the infrared. The wavelength change between holographic recording and reconstruction causes aberrations which could be eliminated by using aspheric waves for the HOE formation [1],[2]. The aspheric waves needed for HOE recording can be obtained by computer-generated holograms (CGH) [3],[4].