Leaky-wave exploration of two-stage switch-on in a nematic pi-cell

Copyright © 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 86 (2005) and may be found at http://link.aip.org/link/?APPLAB/86/052502/1The two-stage switch-on dynamics of a nematic pi-cell are explored in detail using a convergent beam fully-leaky guided mode technique. The cell shows an initial switch-on with a time scale in the range several ms to tens of ms (depending on drive voltage) from the symmetrical H state to a new and semistable H state. It then slowly changes (over several hundred ms) to the final stable asymmetrical H state

Exploration of the surface director profile in a liquid crystal cell using coupling between the surface plasmon and half-leaky optical guided modes

Copyright © 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 92 (2008) and may be found at http://link.aip.org/link/?APPLAB/92/151103/1The half-leaky guided mode geometry with a thin metal tunnel barrier as one cladding layer is used to explore the distribution of the director very near to the surface in a hybrid aligning nematic liquid crystal cell. From theoretical analysis together with numerical modeling, it is shown how the coupled p-polarized surface plasmon/s-like guided modes excited in the geometry leads to extremely sensitive to the surface director tilt profile near the metal wall—a sensitivity which is even higher than that of the surface plasmon resonance alone. The experimental results have fully confirmed the model predictions

Delay effect of switch-on in a supertwisted nematic cell

Copyright © 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 85 (2004) and may be found at http://link.aip.org/link/?APPLAB/85/5070/1By using a convergent beam system and the fully leaky guided mode technique the switch-on dynamics of an 180° supertwisted nematic have been studied. Using the Ericksen–Leslie theory and analyzing the guided mode data taken from the cell, the director structure in the cell at different times during switch-on is obtained. For three different applied voltages it is found that the switch-on time is strongly dependent on the applied field—the higher voltage corresponds to faster switching, with no evidence of backflow. A delay at the beginning of the switch-on process has been found and explored for different applied fields. This leads to a suggestion for increasing the switch-on speed of such devices by 25%

Otto-coupled surface plasmons in a liquid crystal cell

Copyright © 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 95 (2009) and may be found at http://link.aip.org/link/?APPLAB/95/171102/1Surface plasmons on silver in the visible domain are excited using a several micron thick layer of liquid crystal as the optical tunnel barrier. This thickness is possible when the orientation of the director in the liquid crystal varies from homeotropic at the entrance surface (against the coupling prism) to homogeneous on the thick silver layer at the other side of the cell, with the director tilting in a plane normal to the plane of incidence. This geometry also allows the excitation of guided modes, which mixes with the surface plasmon resonance. Both types of mode are then explored as a function of applied voltage

Dynamical process of switch-off in a supertwisted nematic cell

Copyright © 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 96 (2004) and may be found at http://link.aip.org/link/?JAPIAU/96/310/1The switch-off dynamics of a 180° supertwisted nematic (STN) are explored in detail by using a convergent beam system and the fully leaky guided-mode technique. From the dynamical guided-mode data and using the Ericksen–Leslie theory, the director structure in the cell at different times during switch-off is obtained. We have studied the dynamic switch-off from different applied voltages and have found that the relaxation time is independent of the voltage. From fitting the optical data, the effective viscosities are obtained. It appears that two viscosity coefficients, γ and η1, largely control the dynamics of switch-off. From the analysis of the director tilt profile in the cell, it is found that there is no backflow-induced increased tilt at the cell center in the STN cell during the switch-off. From liquid crystal hydrodynamics, this no-backflow dynamic process in the STN cell is well explained

Coupled surface plasmons and optical guided wave exploration of near-surface director profile

Copyright © 2007 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is the published version of an article published in New Journal of Physics Vol. 9, article 49. DOI: 10.1088/1367-2630/9/3/049For a liquid crystal (LC) cell with thin silver claddings it is possible, using a high index coupling prism, to excite both surface plasmon modes and ordinary optical guided modes. In a situation where the tilt of the director varies from homogeneous to homeotropic through the cell, then for p-polarized incident radiation the p-polarized surface plasmon mode and the ordinary guided waves may couple to each other. When the plane containing the director is normal to the incident plane, there is also polarization conversion leading to strong coupling between the p-polarized surface plasmon and s-like guided modes. From theoretical analyses together with numerical modelling it is shown how this coupling between the surface plasmon mode and guided waves gives a high sensitivity to the surface director tilt profile near the walls, higher than that of the surface plasmon mode alone. Experimental confirmation of this has been realized using a hybrid aligned nematic (HAN) LC cell with the director in a plane normal to the incident plane. The results fully confirm the model predictions showing that this coupling of surface plasmons to guided waves provides a powerful tool for near-surface director studies

Vehicle Study with Neural Networks

AbstractThe biology is characteristic of biologic phototaxis and negative phototaxis. Can a machine be endowed with such a characteristic? This is the question we study in this paper, so a method of realizing vehicle's phototaxis and negative phototaxis through a neural network is presented. A randomly generated network is used as the main computational unit. Only the weights of the output units of this network are changed during training. It will be shown that this simple type of a biological realistic neural network is able to simulate robot controllers like that incorporated in Braitenberg vehicles. Two experiments are presented illustrating the stage-like study emerging with this neural network

Molecular pathology and clinical treatment of independent HPV primary serous carcinoma of the uterine cervix (USCC): A case report

Abstract On October 23, 2020, a 69‐year‐old Chinese female patient was admitted to Yuncheng Hospital due to a history of postmenopausal bleeding and lower abdominal pain for 5 months. The HPV test and pathology results indicated the presence of independent HPV in primary serous carcinoma of the uterine cervix. The genetic testing identified variants of uncertain significance (PAX8 p.Tyr 410 Ter and TP53 p.Asn 247 Ile), microsatellite instability stable (MSI‐S), tumor mutational burden (TMB) 7.33Muts/Mb, and an elevated tumor neoantigen burden. Before undergoing radical hysterectomy treatment, the patient exhibited a positive response to three cycles of intravenous docetaxel (100 mg/3 h) and carboplatin (450 mg/1 h). Following the surgery, she received an additional three cycles of docetaxel (100 mg/3 h) and carboplatin (500 mg/1 h), accompanied by 25 cycles of radiation therapy (DT 46Gy/2Gy/23f). Concurrently, cisplatin (450 mg/1 h) was administered. As of now, the patient has achieved 20 months of disease‐free survival