| In recent years, liquid crystal spatial light modulators (LCSLMs) withhigh resolution are more and more introduced to produce programmablediffractive optical elements, and realize dynamic transforms of wavefrontsby displaying the computer-generated holograms on them. This kind of digitalholographic wavefronts transforming method have found widespreadapplications in the fields of exact measurements, three dimensional imaging,microscopy, optical micromanipulation, atomic optics, quantum informationprocessing and so on. The objective of this thesis was to explore thewavefront transformation properties of the twisted nematic liquid crystalspatial light modulators (TN-LCSLMs) and their possible applications,provide academic and experimental base for their applications. The mainpoints of this thesis are as follows:1. Start from the optical properties of the twist nematic liquid crystal material, analyze the modulation principle of a TN-LCSLM, and analyze the polarization transformation properties of a twisted nematic liquid crystal cell (TN-LCC), derive the complex transmission of TN-LCSLM. Represent the TN-LCC as the combination of a rotator and a waveplate, analyze the conditions to get a linear polarization output for a polarized incident light.2. Propose a simple method for precisely measuring the intrinsic parameters of the TN-LCLM based on the special points of its transmittance at field-off state. At the same time, we measure the coherent modulating properties of the TN-LCSLM, including its amplitude and phase modulation versus the gray levels of the control signals, by use of on-axis shearing interferometry for recording the interferograms and a minimum energy... |
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