Twisted-nematic liquid-crystal pixelated active lens
نویسنده
چکیده
Liquid-crystal active lenses are classical imaging systems in which a liquid-crystal spatial light modulator is placed in a pupil plane. The modulator controls the phase of the optical wave in the pupil and achieves an arbitrary wavefront shape, that is limited only by the available modulation depth and resolution. The possibility of using a twisted-nematic liquid-crystal television in the pupil plane is investigated both experimentally and theoretically. The precise evaluation of the modulation characteristics is first discussed. Experimental results obtained both with monochromatic and polychromatic light illustrate the different sampling, quantization and chromatism effects discussed theoretically. Useful models for the computation of the point spread function and the modulation transfer function of a generic pixelated liquid-crystal active imaging system are presented for both in-focus and out-of-focus systems, and their numerical implementation is discussed. q 1998 Elsevier Science B.V. All rights reserved.
منابع مشابه
Fast-response switchable lens for 3D and wearable displays.
We report a switchable lens in which a twisted nematic (TN) liquid crystal cell is utilized to control the input polarization. Different polarization state leads to different path length in the proposed optical system, which in turn results in different focal length. This type of switchable lens has advantages in fast response time, low operation voltage, and inherently lower chromatic aberrati...
متن کاملLiquid Crystals for Electro-optic Applications
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Electro-Optic Response of Liquid Crystals . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. The Liquid Crystalline State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Physical Properties of Liquid Crystals . . . . . . . . . . . . . . . . . . . . . . ....
متن کاملAchromatic polarization switch using a film-compensated twisted nematic liquid crystal cell
A broadband polarization switch consisting of an active twisted nematic liquid crystal cell and two passive uniaxial compensation films is analysed. The conjugate gradient method was used for optimizing the device parameters. Simulation results indicate that the polarization switch exhibits a broad bandwidth and high contrast ratio. The manufacturing tolerances on cell gap, twist angle and comp...
متن کاملHermaphroditic liquid-crystal microlens.
We demonstrate a flat microlens that exhibits hermaphroditic focusing properties. When the input polarization is parallel (perpendicular) to the liquid-crystal directors, the lens exhibits a positive (negative) focal length. To select the proper polarization, we could rotate the polarizer (or the lens) mechanically or by use of an electrically controlled twisted nematic liquid-crystal cell. Det...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998