scholarly journals New Materials Applications in Solar Spectral Analysis

1985 ◽  
Vol 38 (6) ◽  
pp. 781 ◽  
Author(s):  
David M Rust
Keyword(s):  
Liquid Crystals ◽  
Lithium Niobate ◽  
Zeeman Effect ◽  
Automatic Measurement ◽  
New Materials ◽  
Acceptance Angle ◽  
Phase Retardation ◽  
Fabry Perot ◽  
High Voltage Breakdown ◽  
Voltage Breakdown

The use of lithium niobate and liquid crystals in solar instrumentation designed for automatic measurement of spectral line shifts is described. A solid Fabry-Perot etalon of lithium niobate has an acceptance angle 5�3 times greater than an air-spaced Fabry-Perot filter for the same allowed passband broadening, and the lithium niobate device has no moving parts. The use of liquid crystals in Zeeman-effect analysers is also described. For a given phase retardation, liquid crystals require -1/1000 the voltage of solid crystals. They hold promise as reliable, long-lived variable retarders because they are free of the high-voltage breakdown problems of crystals such as potassium dideuterium phosphate (KDP). Progress toward implementation of devices with lithium niobate and liquid crystals in a solar telescope is described.

scholarly journals A Broadband High-Diffraction-Efficiency Electro-Optic Bragg Deflector Based on Monolithic Dual-Grating Periodically-Poled Lithium Niobate

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 242
Author(s):  
An-Chung Chiang ◽  
Yuan-Yao Lin ◽  
Shou-Tai Lin ◽  
Yen-Yin Lin
Keyword(s):  
Lithium Niobate ◽  
Wave Theory ◽  
Beam Radius ◽  
Acceptance Angle ◽  
Periodically Poled ◽  
Periodically Poled Lithium Niobate ◽  
Electro Optic ◽  
Recent Developments ◽  
Strong Focusing ◽  
Grating Design

Electro-optic (EO) Bragg deflectors have been extensively used in a variety of applications. Recent developments show that bandwidths and deflection efficiencies, as well as angular bandwidths, would significantly limit the utilization of EO Bragg deflectors, especially for applications which need strong focusing, such as intra-cavity applications. In this paper, we introduce a broadband EO Bragg deflector based on periodically-poled lithium niobate with a monolithic dual-grating design. We analyzed the deflection properties of this device by using a modified coupled wave theory and showed that this device can be still efficient for a small beam radius under strong focusing, whereas a single-grating one becomes very inefficient. Using a 1064-nm laser beam with a 100-μm beam radius, we obtained a 74% deflection efficiency with a 190-V bias voltage with a 0.5-mm-thick and 7.5-mm-long dual-grating sample. The acceptance angle for the Bragg condition of this device is as large as a few tens of mrad. The potential bandwidth of this device exceeds 500 nm if the proper operation region is chosen.

scholarly journals Optofluidic Platform Based on Liquid Crystals in X-Cut Lithium Niobate: Thresholdless All-Optical Response

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 908
Author(s):  
Fabrizio Ciciulla ◽  
Annamaria Zaltron ◽  
Riccardo Zamboni ◽  
Cinzia Sada ◽  
Francesco Simoni ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Light Intensity ◽  
Lithium Niobate ◽  
Photovoltaic Effect ◽  
Optical Control ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Threshold Behaviour ◽  
All Optical

In this study, we present a new configuration of the recently reported optofluidic platform exploiting liquid crystals reorientation in lithium niobate channels. In order to avoid the threshold behaviour observed in the optical control of the device, we propose microchannels realized in a x-cut crystal closed by a z-cut crystal on the top. In this way, the light-induced photovoltaic field is not uniform inside the liquid crystal layer and therefore the conditions for a thresholdless reorientation are realized. We performed simulations of the photovoltaic effect based on the well assessed model for Lithium Niobate, showing that not uniform orientation and value of the field should be expected inside the microchannel. In agreement with the re-orientational properties of nematic liquid crystals, experimental data confirm the expected thresholdless behaviour. The observed liquid crystal response exhibits two different regimes and the response time shows an unusual dependence on light intensity, both features indicating the presence of additional photo-induced fields appearing above a light intensity of 107 W/m2.

Electrically tunable optical filter for infrared wavelength using liquid crystals in a Fabry–Perot étalon

1990 ◽  
Vol 57 (17) ◽  
pp. 1718-1720 ◽  
Author(s):  
J. S. Patel ◽  
M. A. Saifi ◽  
D. W. Berreman ◽  
Chinlon Lin ◽  
N. Andreadakis ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Optical Filter ◽  
Infrared Wavelength ◽  
Tunable Optical Filter ◽  
Fabry Perot

Laser Fabry-Perot technique for characterization of liquid crystals

2003 ◽  
Author(s):  
Sureshchandra J. Gupta ◽  
Rita A. Gharde ◽  
Anand Tripathi
Keyword(s):  
Liquid Crystals ◽  
Fabry Perot

High voltage breakdown (1.8 kV) of hydrogenated black diamond field effect transistor

2016 ◽  
Vol 109 (20) ◽  
pp. 203504 ◽  
Author(s):  
M. Syamsul ◽  
Y. Kitabayashi ◽  
D. Matsumura ◽  
T. Saito ◽  
Y. Shintani ◽  
...  
Keyword(s):  
High Voltage ◽  
Field Effect ◽  
Field Effect Transistor ◽  
High Voltage Breakdown ◽  
Effect Transistor ◽  
Voltage Breakdown

scholarly journals Amplitude electro-optical modulation of radiation by sequences of Fabry-Perot resonators

2020 ◽  
Vol 56 (2) ◽  
pp. 217-223
Author(s):  
V. B. Zalesski ◽  
A. I. Konoiko ◽  
V. M. Kravchenko ◽  
H. S. Kuzmitskaya
Keyword(s):  
Lithium Niobate ◽  
High Efficiency ◽  
Optical Modulation ◽  
Operating Point ◽  
Optical Modulator ◽  
Control Voltage ◽  
Clock Frequency ◽  
Fabry Perot ◽  
In Series ◽  
Light Signals

In this paper, we considered the method of amplitude electro-optical modulation of radiation using sequences of Fabry-Perot resonators based on the transverse electro-optical effect on the example of lithium niobate LiNbO3. With this method, it is possible to significantly reduce the voltage of the control electromagnetic field of the electro-optical amplitude modulator operating in the transmission mode of the light beam while maintaining its high efficiency. The reduction of the control voltage is achieved by increasing the number of Fabry-Perot resonators installed in series and the phase shift relative to the extremum of the transmittance function. This method allows to diminish the duration of the received light signals which leads to an increase in the clock frequency while maintaining a high efficiency of the radiation modulation. Diminishing the duration of light signals is achieved by using separate modulation channels of two sequences of electro-optical Fabry-Perot resonators, the first of which works on the transmission and the second one on the reflection. Increasing the clock frequency at the output of the modulator is achieved by summing the signals coming from several modulation channels. It is shown that the value of the control voltage for an amplitude electro-optical modulator based on a sequence of Fabry-Perot resonators made of lithium niobate LiNbO3, with an operating wavelength of 1.307 microns, can be 4 V in the case when its initial operating point corresponds to the maximum transmittance. The control voltage is 2 V if the initial operating point is shifted in phase relative to the extremum of the transmittance function.

ChemInform Abstract: Imidazolium-Based Liquid Crystals: A Modular Platform for Versatile New Materials with Finely Tuneable Properties and Behavior

ChemInform ◽  
2012 ◽  
Vol 43 (15) ◽  
pp. no-no
Author(s):  
Laurent Douce ◽  
Jean-Moise Suisse ◽  
Daniel Guillon ◽  
Andreas Taubert
Keyword(s):  
Liquid Crystals ◽  
New Materials ◽  
Modular Platform ◽  
And Behavior

HIGH VOLTAGE BREAKDOWN STUDY

1968 ◽  
Author(s):  
W. R. Bell ◽  
M. J. Mulcahy ◽  
F. Y. Tse ◽  
A. Watson
Keyword(s):  
High Voltage ◽  
High Voltage Breakdown ◽  
Voltage Breakdown
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