Liquid crystal spatial light modulators

Wefers M M and Nelson K A 1995 Analysis of programmable ultrashort waveform generation using liquid-crystal spatial light modulators J. Opt. Soc. Am. B 12 1343-62... 

Besides polyimides, photoconductive polymers with conjugated bonds also can be successfully used in liquid crystal spatial light modulators [262-264], The high resolution, mechanical and electrical stability and possibility for sensitization of the photosensitivity make the use of organic polymer photoconductors in spatial light modulators very attractive. Devices such as phase... 

Polymers, with their unique case of processability have good potential for use in different electro-optic devices. Tlie polysilane-liquid crystal spatial light modulator is another example of what can be done in this area and the great potential for development. 

L. Dinescu, R.P. Lemieux, Optical Switching of a ferroelectric liquid crystal spatial light modulator by photoinduced polarization inversion. Adv. Mater. 11, 42-45 (1999)... 

Ahderom S. Raisi M. et al.. 0ul 2002) "Ap>plications of Liquid Crystal Spatial Light Modulators in Optical Communications", 5th International Conference on High Speed Networks and Multimedia Comm., 3-5, pp 239-242 Agrawal, G.P. (2002) "Fiber-Optic Communication Systems" (Third Edition), Wiley... 

Figure 13.13. Optically addressed liquid crystal spatial light modulator.

A.A. Vasil yev, Yu.K. Gruzevich,. S.N. Levov, A.V. Parfenov, and V.G. Chigrinov, Resolution of liquid crystal spatial light modulators computer simulation and experimental data. Preprint no. 1, Lebedev s Physical Institute, Moscow, 1986. 

D. C. Tilotta, R. M. Hammaker, W. G. Fateley. A visible-near-infrared Hadamard transform spectrometer based on a liquid crystal spatial light modulator array A new approach in... 

Drabik, T.J., et al., 2D Silicon/Ferroelectric Liquid Crystal Spatial Light Modulators. IEEE Micro, 1995. IS p. 67-76. 

The main non-display applications of liquid crystals can be subdivided into two classes. The first exploits their anisotropic optical properties in spatial light modulators or their nonlinear optical properties in optical wave mixing etc. Spatial light modulators are usually based on the ferroelectric SmC phase aligned in a thin film. Liquid crystal spatial light modulators may soon find advanced applications such as the storage of... 

There are many nondisplay applications of liquid crystals, and it is not possible to do justice to aU of them here in this section. Here we will outline some key examples, and summarize briefly a wider selection. Some of the most developed applications that are currently being researched are in optical correlators, optical interconnections, wavelength filters, and optoelectronic neural networks. Most of these systems use liquid crystal spatial light modulators (SLMs). In addition, we will describe how SLMs are used in autostereoscopic displays. 

Any device that controls the amount of light that passes through the device is called a light valve. A device that allows the transmittance to be independently controlled at different locations is called a spatial light modulator (SLM). An important example of such devices is an image projection system. If these projection systems are based on liquid crystals, we call them liquid crystal spatial light modulators (LCSLM). LCSLMs may be electrically controlled by a matrix of pixels or by the intensity of the light incident on the device. 

Sun J, Wu TS (2014) Recent advances in polymer network liquid crystal spatial light modulators. J Polym Sci B Polym Phys 52 183-192... 

Figure 6.12 shows the schematic constraction of a typical optically addressed liquid crystal spatial light modulator (OALCSLM) operating in the reflective mode. It consists of an aligned liquid crystal layer sandwiched between transparent electrodes and adjacent to a photoconducting semiconductor layer (a-Si H) sensitive to the writing beams and a dielectric mirror coated to block the reading beam. 

As one can see from the preceding discussions on optical field induced director axis reorientation in hquid crystals, the torque exerted by the optical field on the director axis is basically quadratic in the field amplitude. Except for its dispersion influence on the optical dielectric constant 8(co), the frequency of the electric field is basically not involved. Furthermore, if two or more fields are acting on the director axis, the resulting torque exerted on the director axis is simply proportional to the square amplitude of the total fields. Accordingly, it is possible to enhance the optical field induced effect by application of a low-frequency ac or dc electric field, much as the optically addressed liquid crystal spatial light modulator discussed in Chapter 6. In the latter, the responsible mechanism is the photoconduction generated by the incident optical field in the semicondnctor layer adjacent to the liquid crystals. 

Table 12.3. Comparison of the Performance Characteristics of Commercial Liquid Crystal Spatial Light Modulator (LCSLM) with What Could he Expected of Dye-Doped Liquid Crystal (DDLC) Film...

Among the various material systems that make up smart pixels, liquid crystals are particularly interesting because of their transparency, broadband electro-optical response, and other unique material properties. Liquid crystal on silicon (LCOS) devices, liquid crystal spatial light modulators (LCSLMS), incorporating neural net functions enabled by the backplane electronics and inter- and intrapixel electronic cormections, such as optoelectronic neuron array, LC/silicon retina, and winner take-all circuit, have been developed previously. In these devices, the photosensitivity needed for sensing the input comes from the photoconductive layer processed into... 

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