Paper
11 September 1998 Electronic control system exploiting both the dual-frequency effect and the transient nematic effect for a fast 127-element nematic liquid crystal spatial light modulator
Scot W. McDermott, Samuel C. Rogers, John D. Gonglewski, Stephen L. Browne
Author Affiliations +
Abstract
Nematic liquid crystals have been sued as phase retarders in adaptive optics system for more than 10 years. Liquid crystal spatial light modulators (SLMs) can be very useful both as controlled disturbances for characterizing adaptive optics systems, and as wavefront correctors. Of the available options, SLMs have the advantages of low cost, reliability, compactness, low power, ease of controllability, optical transmissivity, and simple aperture scalability. Moreover, these devices are very non-linear and normally have quite different response times in the increasing versus the decreasing phase direction. The current limitation for using these devices in atmospheric adaptive systems is their relatively slow response times, not only for small phase steps in the excitation direction, but for all steps in the relaxation direction. The response time in both directions can be significantly improved by exploiting two important properties of certain nematic liquid crystals: the Dual-Frequency Effect and the Transient Nematic Effect. This paper presents the details of custom- built electronic hardware that takes advantage of these two effects to implement (lambda) /10 phase accuracy with millisecond settling time for both increasing and decreasing phase shifts.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Scot W. McDermott, Samuel C. Rogers, John D. Gonglewski, and Stephen L. Browne "Electronic control system exploiting both the dual-frequency effect and the transient nematic effect for a fast 127-element nematic liquid crystal spatial light modulator", Proc. SPIE 3353, Adaptive Optical System Technologies, (11 September 1998); https://doi.org/10.1117/12.321695
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KEYWORDS
Liquid crystals

Crystals

Spatial light modulators

Adaptive optics

Molecules

Control systems

Field programmable gate arrays

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