Optically Controlled Space Charge Fields under the Electrode Region in Cadmium Telluride

1992 ◽  
Vol 261 ◽  
Author(s):  
Mehrdad Ziari ◽  
William H. Steier
Keyword(s):  
Simple Model ◽  
Space Charge ◽  
Cadmium Telluride ◽  
Field Distribution ◽  
Electric Fields ◽  
Spatial Light Modulators ◽  
Electrode Region ◽  
Light Modulators ◽  
Controlled Switching ◽  
Switching Devices

We report an optically controlled and space-charge related formation and erasure of large electric fields in the electrode region of CdTe:In. The measurement of the field distribution under different illumination conditions can be explained by a simple model. This nonlinearity has been used in optically controlled switching devices and spatial light modulators.

The structure of the impulse corona in a rod/plane gap. II. The negative corona: propagation and streamer/anode interaction

1979 ◽  
Vol 367 (1730) ◽  
pp. 321-342 ◽  
Keyword(s):  
Simple Model ◽  
Electric Field ◽  
Space Charge ◽  
Electric Fields ◽  
Electric Field Distribution ◽  
Electron Lifetime ◽  
Gas Temperature ◽  
Negative Corona ◽  
Negative Impulse ◽  
Total Electric Field

The electric fields due to negative impulse corona space charge in a 0.5 m rod/plane gap have been investigated with a rotating fluxmeter probe. Spatial development has also been studied by simultaneous photography. The results indicate that a total electric field of about 1.8 MV m-1 is required near the head of the streamer for propagation, and a simple model is proposed of the electric field distribution in the gap at various stages of development. Measurements of transfer charge, due to interaction of streamers with the plane, yield estimates of the free electron lifetime and the gas temperature in the streamer. Possible models of the charge distribution in streamers are considered, with their associated electric fields, and best agreement with the data is obtained when most of the space charge is assumed to be concentrated at the tip. Comparison is made with earlier work on positive coronas.

scholarly journals A self-healing ferroelectric liquid crystal electro-optic shutter based on vertical surface-relief grating alignment

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peter J. M. Wyatt ◽  
James Bailey ◽  
Mamatha Nagaraj ◽  
J. Cliff Jones
Keyword(s):  
Adaptive Optics ◽  
Electric Fields ◽  
Surface Relief ◽  
High Speed ◽  
Spatial Light Modulators ◽  
Smectic Layer ◽  
Self Healing ◽  
Surface Relief Grating ◽  
Light Modulators ◽  
Induced Flow

AbstractFerroelectric liquid crystals remain of interest for display and spatial light modulators because they exhibit significantly faster optical response times than nematics. However, smectic layers are sensitive to shock-induced flow and are usually permanently displaced once a well-aligned sample is disrupted, rendering such devices inoperable. We introduce a vertical alignment geometry combined with a surface-relief grating to control both the smectic layer and director orientations. This mode undergoes “self-healing” of the smectic layers after disruption by shock-induced flow. Sub-millisecond switching between optically distinct states is demonstrated using in-plane electric fields. Self-healing occurs within a second after being disrupted by shock, wherein both the layer and director realign without additional external stimulus. The route to material improvements for optimised devices is discussed, promising faster spatial light modulators for high-speed adaptive optics, micro-displays for virtual/augmented reality and telecommunications with inherent shock stability.

Giant Anisotropy of Conductivity in Hydrogenated Nanocrystalline Silicon Thin Films

1998 ◽  
Vol 536 ◽  
Author(s):  
A. B. Pevtsov ◽  
N. A. Feoktistov ◽  
V. G. Golubev
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Percolation Theory ◽  
Nanocrystalline Silicon ◽  
Spatial Light Modulators ◽  
Light Emitting ◽  
Light Modulators ◽  
Silicon Thin Films ◽  
Longitudinal Conductivity ◽  
Transverse Conductivity

AbstractThin (<1000 Å) hydrogenated nanocrystalline silicon films are widely used in solar cells, light emitting diodes, and spatial light modulators. In this work the conductivity of doped and undoped amorphous-nanocrystalline silicon thin films is studied as a function of film thickness: a giant anisotropy of conductivity is established. The longitudinal conductivity decreases dramatically (by a factor of 109 − 1010) as the layer thickness is reduced from 1500 Å to 200 Å, while the transverse conductivity remains close to that of a doped a- Si:H. The data obtained are interpreted in terms of the percolation theory.

Field distribution in polymeric MV-HVDC model cable under temperature gradient. Simulation and space charge measurements

2014 ◽  
Vol 17 (5-6) ◽  
pp. 307-325 ◽  
Author(s):  
Thi Thu Nga Vu ◽  
Gilbert Teyssedre ◽  
Bertrand Vissouvandin ◽  
Séverine Le Roy ◽  
Christian Laurent ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Space Charge ◽  
Field Distribution

scholarly journals Ag-Yb Alloy-Novel Tunable Plasmonic Material

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 288
Author(s):  
Suetying Ching ◽  
Chakming Chan ◽  
Jack Ng ◽  
Kokwai Cheah
Keyword(s):  
Beam Steering ◽  
Volume Ratio ◽  
Response Strength ◽  
Transmission Efficiency ◽  
Spatial Light Modulators ◽  
Alloy Thin Film ◽  
Ellipsometric Measurement ◽  
Plasmonic Material ◽  
Light Modulators ◽  
Surface Plasmon Coupling

Metals are commonly used in plasmonic devices because of their strong plasmonic property. However, such properties are not easily tuned. For applications such as spatial light modulators and beam steering, tunable plasmonic properties are essential, and neither metals nor other plasmonic materials possess truly tunable plasmonic properties. In this work, we show that the silver alloy silver–ytterbium (Ag-Yb) possesses tunable plasmonic properties; its plasmonic response strength can be adjusted as a function of Yb concentration. Such tunability can be explained in terms of the influence of Yb on bound charge and interaction of its dielectric with the dielectric of Ag. The change in transition characteristics progressively weakens Ag’s plasmonic properties. With a spectral ellipsometric measurement, it was shown that the Ag-Yb alloy thin film retains the properties of Ag with high transmission efficiency. The weakened surface plasmon coupling strength without dramatic change in the coupling wavelengths implies that the tunability of the Ag-Yb alloy is related to its volume ratio. The principle mechanism of the plasmonic change is theoretically explained using a model. This work points to a potential new type of tunable plasmonic material.

scholarly journals Holographic Display System to Suppress Speckle Noise Based on Beam Shaping

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 204
Author(s):  
Di Wang ◽  
Yi-Wei Zheng ◽  
Nan-Nan Li ◽  
Qiong-Hua Wang
Keyword(s):  
Optical Element ◽  
Speckle Noise ◽  
Beam Shaping ◽  
Diffractive Optical Element ◽  
The Other ◽  
Spatial Light Modulators ◽  
Viewing Angle ◽  
Display System ◽  
Holographic Display ◽  
Light Modulators

In this paper, a holographic system to suppress the speckle noise is proposed. Two spatial light modulators (SLMs) are used in the system, one of which is used for beam shaping, and the other is used for reproducing the image. By calculating the effective viewing angle of the reconstructed image, the effective hologram and the effective region of the SLM are calculated accordingly. Then, the size of the diffractive optical element (DOE) is calculated accordingly. The dynamic DOEs and effective hologram are loaded on the effective regions of the two SLMs, respectively, while the wasted areas of the two SLMs are performed with zero-padded operations. When the laser passes through the first SLM, the light can be modulated by the effective DOEs. When the modulated beam illuminates the second SLM which is loaded with the effective hologram, the image is reconstructed with better quality and lower speckle noise. Moreover, the calculation time of the hologram is reduced. Experiments indicate the validity of the proposed system.

scholarly journals A Simple Gas-Kinetic Model For Dilute and Weakly Charged Plasma Micro-Jet Flows

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 250
Author(s):  
Shiying Cai ◽  
Chunpei Cai
Keyword(s):  
Simple Model ◽  
Electric Fields ◽  
Neutral Condition ◽  
Jet Flows ◽  
Far Field ◽  
Convection Term ◽  
Number Density ◽  
Simulation Based ◽  
Analytical Formulas ◽  
Electric Field Force

This paper presents a simple model for slightly charged gas expanding into a vacuum from a planar exit. The number density, bulk velocity, temperature, and potential at the exit are given. The electric field force is assumed weaker than the convection term and is neglected in the analysis. As such, the quasi-neutral condition is naturally adopted and the potential field is computed with the Boltzmann relation. At far field, the exit degenerates as a point source, and simplified analytical formulas for flow and electric fields are obtained. The results are generic and offer insights on many existing models in the literature. They can be used to quickly approximate the flowfield and potential distributions without numerical simulations. They can also be used to initialize a simulation. Based on these results, more advanced models may be further developed.

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