Optical beam steering using a liquid‐crystal television panel

Tanone, Aris; Zhang, Z.; Uang, Chii-Maw; Yu, Francis T. S.; Gregory, Don A.

doi:10.1002/mop.4650070610

Cited by 7 publications

(4 citation statements)

References 8 publications

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“…Figure 6A shows the illustration of the cell and the spatially varying director formed when field is applied while Figure 6B shows the photomicrograph of the phase grating between crossed polarizers. [70] However, if the desired application needs large steering angles, the LC-phased array [71] presents problems since the diffraction efficiency drops considerably as the steered angle increases. On the other hand, positive orders had a lower efficiency, a characteristic of blazed gratings (diffraction gratings optimized for high efficiency of a determined diffraction order).…”

Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

“…The steering effect can be observed for spatial light modulators (SLMs) or even TV panels. [70] Copyright 2000, Optical Society of America. [72] For example, beam steering device consisting of an array illuminator and an LC grating was reported to have 76% efficiency; however, the steered angle is less than 1°.…”

Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

“…The steering effect can be observed for spatial light modulators (SLMs) or even TV panels. [70] However, if the desired application needs large steering angles, the LC-phased array [71] presents problems since the diffraction efficiency drops considerably as the steered angle increases. [72] For example, beam steering device consisting of an array illuminator and an LC grating was reported to have 76% efficiency; however, the steered angle is less than 1°.…”

Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

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Dynamic Control of Light Direction Enabled by Stimuli‐Responsive Liquid Crystal Gratings

et al. 2018

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the duality consolidation, the idea of controlling light and how it interacts with matter has always been an exciting topic. Visible light, as we perceive it, is a small portion of the electromagnetic spectrum composed of mutually perpendicular oscillating electric and magnetic fields that propagate through space and presents wave-like and particle-like behavior. Since the elements comprising matter possess dynamic electron clouds, the electromagnetic nature of light prompts different responses when it interacts with different materials, depending on its intensity, frequency, the arrangement of molecules, and so on. Whenever light interacts with matter, it might be absorbed, re-emitted, scattered, or transmitted. Although these effects are well known, the combination of them with new, innovative materials pushes optics forward. In fact, advances in optics have often occurred through the development of materials with improved optical properties, thus creating remarkable applications that tremendously influence our daily lives. These exciting applications include image processing and recording, lasing, data storage, display devices, detector systems, propulsion systems, and optical tweezers, which have enabled remote micromanipulation of colloidal particles and promising applications in various biomedical and biological applications. [1][2][3] There is, however, one component that stands out: the diffraction grating. It is generally regarded as one of the most important devices in the development of several fields of science. [4] Such importance comes from the fact that a diffraction grating is a device with a periodic structure capable of changing the propagation and splitting the spectrum The ability to control light direction with tailored precision via facile means is long-desired in science and industry. With the advances in optics, a periodic structure called diffraction grating gains prominence and renders a more flexible control over light propagation when compared to prisms. Today, diffraction gratings are common components in wavelength division multiplexing devices, monochromators, lasers, spectrometers, media storage, beam steering, and many other applications. Next-generation optical devices, however, demand nonmechanical, full and remote control, besides generating higher than 1D diffraction patterns with as few optical elements as possible. Liquid crystals (LCs) are great candidates for light control since they can form various patterns under different stimuli, including periodic structures capable of behaving as diffraction gratings. The characteristics of such gratings depend on several physical properties of the LCs such as film thickness, periodicity, and molecular orientation, all resulting from the internal constraints of the sample, and all of these are easily controllable. In this review, the authors summarize the research and development on stimuli-controllable diffraction gratings and beam steering using LCs as the active optical materials. Dynamic gratings fabricated by applying external f...

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Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

Section: Surface Template and Electric Field-driven Gratingsmentioning

confidence: 99%

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Dynamic Control of Light Direction Enabled by Stimuli‐Responsive Liquid Crystal Gratings

et al. 2018

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“…A number of devices have been demonstrated based on the switching of a layer of planar nematic liquid crystal to produce a periodic spatially varying phase profile [3][4][5][6][7][8] . When no voltages are applied the molecular director of the nematic liquid crystal through the layer is oriented along a direction pre-determined by unidirectional rubbing of the substrates.…”

Section: Nematic Liquid Crystal Phase Gratingsmentioning

confidence: 99%

Flexoelectric polarisation effects in nematic liquid crystal phase gratings

et al. 2008

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Nematic phase gratings have been studied in which a planar nematic layer of thickness 17.2 μm is sandwiched between two glass substrates coated with an alignment polymer. The upper substrate is a continuous earth plane and the lower substrate has a patterned electrode of interdigitated stripes (electrodes and gaps are both 40 μm wide). Reorientation of the nematic liquid crystal occurs in response to d.c. electric fields applied between the interdigitated electrodes. These nematic reorientation regions have been used to investigate the influence of the flexoelectric polarisation in the nematic liquid crystal by observing the resultant (i) movement of tilt fringes in a Mach-Zehnder interferometer, and (ii) optical diffraction patterns. In the Mach-Zehnder interferometer the periodic variation of the refractive index resulting from the periodic distortion profile is measured directly from the displacement of the tilt fringes. The asymmetry in the response to positive and negative polarities of the d.c. voltage for both measurement techniques is directly related to the sum of the flexoelectric coefficients, e 1 + e 3 .

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