Fringing fields in a liquid crystal spatial light modulator for beam steering

Hällstig, Emil; Stigwall, Johan; Martin, T.; Sjöqvist, Lars; Lindgren, Mikael

doi:10.1080/09500340408230419

Cited by 34 publications

(15 citation statements)

References 18 publications

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“…As such systems tend to be large, heavy and complex, a non-mechanical all-electronic beam steering component would often be preferred [1]. The use of very-large-scale integration (VLSI) technology in conjunction with new mixtures of Liquid Crystals (LC) has recently led to the construction of polarisation-insensitive Opto-VLSI processors capable of steering, splitting and reshaping optical beams [1]. Opto-VLSI processors have several properties that are attractive for laser beam steering including a small pixel size, low-switching voltage, low power consumption, and high optical efficiency [2].…”

Section: Introductionmentioning

confidence: 99%

Improving the steering efficiency of 1/spl times/4096 opto-VLSI processor using direct power measurement method

Poll

Alameh

2006

Third IEEE International Workshop on Electronic Design, Test and Applications (DELTA'06)

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We report optimization of the steering efficiency of the 1-D Opto-VLSI processor using direct power measurement method for wavelengths in the near-IR and 632 nm. Highest improvement observed for the signal and interport isolation is 8 dB and 12 dB respectively. This improved performance of the processor is crucial to the realization of low crosstalk reconfigurable optical add/drop multiplexers (ROADM) using Opto-VLSI processors.

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Section: Introductionmentioning

confidence: 99%

Improving the steering efficiency of 1/spl times/4096 opto-VLSI processor using direct power measurement method

Poll

Alameh

2006

Third IEEE International Workshop on Electronic Design, Test and Applications (DELTA'06)

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“…Experimental verification of the voltage optimization method has also been performed. In one study by E. Haellstig [64], a LC SLM with 1 × 4096 small stripe shaped pixels (1.8 µm) was studied. By using the voltage profile optimization method, the diffraction efficiency could be improved significantly.…”

Section: Fringing Field Effectmentioning

confidence: 99%

LCoS SLM Study and Its Application in Wavelength Selective Switch

et al. 2017

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Abstract:The Liquid-Crystal on Silicon (LCoS) spatial light modulator (SLM) has been used in wavelength selective switch (WSS) systems since the 1990s. However, most of the LCoS devices used for WSS systems have a pixel size larger than 6 µm. Although there are some negative physical effects related to smaller pixel sizes, the benefits of more available ports, larger spatial bandwidth, improved resolution, and the compactness of the whole system make the latest generation LCoS microdisplays highly appealing as the core component in WSS systems. In this review work, three specifications of the WSS system including response time, crosstalk and insertion loss, and optimization directions are discussed. With respect to response time, the achievements of liquid crystal material are briefly surveyed. For the study of crosstalk and insertion loss, related physical effects and their relation to the crosstalk or insertion loss are discussed in detail, preliminary experimental study for these physical effects based on a small pixel LCoS SLM device (GAEA device, provided by Holoeye, 3.74 µm pixel pitch, 10 megapixel resolution, telecom) is first performed, which helps with predicting and optimizing the performance of a WSS system with a small pixel size SLM. In the last part, the trend of LCoS devices for future WSS modules is discussed based on the performance of the GAEA device. Tradeoffs between multiple factors are illustrated. In this work, we present the first study, to our knowledge, of the possible application of a small pixel sized SLM as a switching component in a WSS system.

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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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Fringing fields in a liquid crystal spatial light modulator for beam steering

Cited by 34 publications

References 18 publications

Improving the steering efficiency of 1/spl times/4096 opto-VLSI processor using direct power measurement method

Improving the steering efficiency of 1/spl times/4096 opto-VLSI processor using direct power measurement method

LCoS SLM Study and Its Application in Wavelength Selective Switch

Flexoelectric polarisation effects in nematic liquid crystal phase gratings

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