Application of Holographic Optical Elements in Optical Memory Devices

Computer generated Holographic Optical Elements (HOE) have been written by e-beam lithography on Al2O3 waveguides. The spectral bandwidth of HOE with Separate Input and Output Couplers (SIOC-HOE) was 0.7 nm compared to more than 9 nm of HOE with Convolved Input and Output Coupler (CIOC-HOE). The beam waist in the focus can be explained in terms of the natural beam waist and the spectral displacement of the focal point. The coupling efficiency of HOEs with beam splitting characteristic could be modeled. An integrated pickup device for an optical storage medium was realized with CIOC-HOEs.