Temperature-dependent chirality of cholesteric liquid crystal for terahertz waves

Xin Zhang; Fei Fan; Yun-Yun Ji; Sheng-Jiang Chang

doi:10.1364/ol.402226

Synthesis and Characterization of a Cholesteric Liquid Crystal Cholesteryl Nonanoate

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.428-429.94 ◽

2010 ◽

Vol 428-429 ◽

pp. 94-97 ◽

Cited By ~ 4

Author(s):

Yuan Ming Huang ◽

Ye Tang Guo ◽

Qing Lan Ma ◽

Wei Wei Liu

Keyword(s):

Liquid Crystal ◽

Cholesteric Liquid Crystal ◽

Synthesis And Characterization ◽

Temperature Dependent ◽

Scanning Calorimetry ◽

Selective Reflection ◽

Cholesteric Phase ◽

Polarized Optical Microscopy ◽

Clearing Point

A cholesteric liquid crystal cholesteryl nonanoate was synthesized and then characterized by means of differential scanning calorimetry and polarized optical microscopy. As temperature decreased from its clearing point, cholesteric phase was formed for cholesteryl nonanoate and accompanied by continuous evolution of colors in the focal conic textures. Furthermore, beautiful spherulite crystals were observed to grow out of the cholesteric phase as the crystallization continued. The evolution of the colors in recorded textures was contributed to temperature-dependent selective reflection of the liquid crystal.

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Temperature dependent color cone lasing in cholesteric liquid crystal

2013 Conference on Lasers and Electro-Optics Pacific Rim (CLEOPR) ◽

10.1109/cleopr.2013.6600475 ◽

2013 ◽

Cited By ~ 1

Author(s):

Po-Yen Chen ◽

Kuan-Cheng Liao ◽

Ja-Hon Lin ◽

Yao-Hui Chen ◽

Shwu-Yun Tsay Tzeng ◽

...

Keyword(s):

Liquid Crystal ◽

Cholesteric Liquid Crystal ◽

Temperature Dependent

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Experimental Verification of Vuks Equation Using Hollow Prism Refractometer

Journal of Atomic Molecular and Optical Physics ◽

10.1155/2012/689831 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6

Author(s):

Anita Kanwar ◽

Priya S. Yadav

Keyword(s):

Liquid Crystal ◽

Temperature Dependence ◽

Experimental Verification ◽

Cholesteric Liquid Crystal ◽

Visible Range ◽

Refractive Indices ◽

Temperature Dependent ◽

Crystalline Materials ◽

Different Temperatures ◽

Molecular Polarizabilities

The refractive indices of the cholesteric liquid crystal solution were measured using multiwavelength (visible range) refractometer for three different wavelengths. Measurements were made at different temperatures for various concentrations of the solution, mixing CLC in a soluble solvent. Vuks equation describes the wavelength and temperature dependence of refractive indices of anisotropic crystalline materials. We have used a simplified version of Vuks equation relating only to macroscopic indices and verified its validity for five-different-concentration solution at various temperatures. The result is also used to obtain molecular polarizabilities and temperature dependent material constants of our sample.

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Dispersion of proton spin-lattice relaxation in a cholesteric liquid crystal

Journal de Physique ◽

10.1051/jphys:0198300440100117900 ◽

1983 ◽

Vol 44 (10) ◽

pp. 1179-1184 ◽

Cited By ~ 16

Author(s):

M. Vilfan ◽

R. Blinc ◽

J. Dolinšek ◽

M. Ipavec ◽

G. Lahajnar ◽

...

Keyword(s):

Liquid Crystal ◽

Cholesteric Liquid Crystal ◽

Lattice Relaxation ◽

Proton Spin ◽

Spin Lattice Relaxation ◽

Spin Lattice

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Flow-assisted self-healing of the helical structure in a cholesteric liquid crystal

The Journal of Chemical Physics ◽

10.1063/5.0058745 ◽

2021 ◽

Vol 155 (5) ◽

pp. 054903

Author(s):

Jan-Christoph Eichler ◽

Robert A. Skutnik ◽

Marco G. Mazza ◽

Martin Schoen

Keyword(s):

Liquid Crystal ◽

Cholesteric Liquid Crystal ◽

Helical Structure ◽

Self Healing

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Temperature Characterization of Liquid Crystal Dielectric Image Line Phase Shifter for Millimeter-Wave Applications

Crystals ◽

10.3390/cryst11010063 ◽

2021 ◽

Vol 11 (1) ◽

pp. 63

Author(s):

Henning Tesmer ◽

Rani Razzouk ◽

Ersin Polat ◽

Dongwei Wang ◽

Rolf Jakoby ◽

...

Keyword(s):

Liquid Crystal ◽

Millimeter Wave ◽

Insertion Loss ◽

Phase Shifter ◽

Ground Plane ◽

Temperature Dependent ◽

Differential Phase ◽

Dependent Behavior ◽

The Impact ◽

Temperature Dependent Behavior

In this paper we investigate the temperature dependent behavior of a liquid crystal (LC) loaded tunable dielectric image guide (DIG) phase shifter at millimeter-wave frequencies from 80 GHz to 110 GHz for future high data rate communications. The adhesive, necessary for precise fabrication, is analyzed before temperature dependent behavior of the component is shown, using the nematic LC-mixture GT7-29001. The temperature characterization is conducted by changing the temperature of the LC DIG’s ground plane between −10∘C and 80 ∘C. The orientation of the LC molecules, and therefore the effective macroscopic relative permittivity of the DIG, is changed by inserting the temperature setup in a fixture with rotatable magnets. Temperature independent matching can be observed, while the insertion loss gradually increases with temperature for both highest and lowest permittivity of the LC. At 80 ∘C the insertion loss is up to 1.3dB higher and at −10∘C it is 0.6dB lower than the insertion loss present at 20 ∘C. In addition, the achievable differential phase is reduced with increasing temperature. The impact of molecule alignment to this reduction is shown for the phase shifter and an estimated 85% of the anisotropy is still usable with an LC DIG phase shifter when increasing the temperature from 20 ∘C to 80 ∘C. Higher reduction of differential phase is present at higher frequencies as the electrical length of the phase shifter increases. A maximum difference in differential phase of 72∘ is present at 110 GHz, when increasing the temperature from 20 ∘C to 80 ∘C. Nevertheless, a well predictable, quasi-linear behavior can be observed at the covered temperature range, highlighting the potential of LC-based dielectric components at millimeter wave frequencies.

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