Improve on the uniformity of reconstructed output from computer generated hologram with a pre-compensate method

Mei-Li Hsieh and Hung-Chia Liao
National Taiwan Normal University, Taiwan
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The main advantage of the computer generated hologram (CGH) is that it is easy to design and fabricate the hologram without real objects and optical system. There are few techniques to display the hologram generated by computer, such as the micro-lithographic technique or spatial light modulator. Among these two techniques, the distribution of CGH is fabricated or display in these devices which with pixelated structure. Hence, the uniformity of the reconstructed image is modified by the sinc function due to the pixelated structure of the display devices for the computer generated hologram (CGH). To minimize and compensate the uniformity, we proposed a pre-compensate method for CGH, which is designed using the Iterative Fourier Transformation Algorism (IFTA). In this contribution, the pre-compensated method for binary phase CGH will be presented. Also, the optical properties of the reconstructed image from binary phase CGH with the pre-compensate method will be discussed and compare with the reconstructed images without the pre-compensate method. In addition, the optical reconstructed system will be setup using the spatial light modulator to display the binary phase CGH, and the experimental results will be demonstrated. The uniformity of the reconstructed image with the pre-compensate method will be measured and discussed.