scholarly journals Electrical tuning of the LC:PDMS channels

2017 ◽  
Vol 9 (2) ◽  
pp. 48 ◽  
Author(s):  
Katarzyna Agnieszka Rutkowska ◽  
Tomasz R. Woliński ◽  
Rita Asquini ◽  
Luca Civita ◽  
Luca Martini ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Integrated Circuits ◽  
Optical Waveguides ◽  
Optical Switching ◽  
Liquid Crystalline ◽  
Optical Switch ◽  
Optical Parameters ◽  
Directional Couplers ◽  
Optical Mems ◽  
Experimental Trials

In this paper studies on electrical tuning of optical channels formed by the PDMS-based waveguides infiltrated with liquid crystalline material are presented. In particular, preliminary results of numerical simulations demonstrating changes in optical parameters of the waveguide channels when influenced by electric field applied via flat and IPS electrodes are demonstrated in order to fabricate photonic switches based on optical directional couplers. First experimental trials of sputtering the ITO layer on PDMS substrate are also shown. Full Text: PDF ReferencesG. Wypych, Handbook of polymers (Elsevier 2016). CrossRef J.C. McDonald, D.C. Duffy, J.R. Anderson, D.T. Chiu, H. Wu, O.J. Schueller, G.M. Whitesides, "Fabrication of microfluidic systems in poly(dimethylsiloxane)", Electrophoresis 21, 27 (2000). CrossRef Y. Fainman, L. Lee, D. Psaltis, C. Yang, Optofluidics: fundamentals, devices, and applications (McGraw-Hill, Inc., 2009).I. Khoo, Liquid crystals: physical properties and nonlinear optical phenomena (John Wiley & Sons, 2007). CrossRef A. d'Alessandro, L. Martini, L. Civita, R. Beccherelli, R. Asquini, "Liquid crystal waveguide technologies for a new generation of low-power photonic integrated circuits", Proc. SPIE 9384, 93840L (2015). CrossRef R. Asquini, L. Martini, A. d'Alessandro, "Fabrication and Characterization of Liquid Crystal Waveguides in PDMS Channels for Optofluidic Applications", Mol. Cryst. Liquid Cryst. 614, 11 (2015). CrossRef B. Bellini, J. F. Larchanché, J. P. Vilcot, D. Decoster, R. Beccherelli, A. d'Alessandro, "Photonic devices based on preferential etching", Applied Optics, 44, (33), (2005). CrossRef L. De Sio, J.G. Cuennet, A.E. Vasdekis, D. Psaltis, "All-optical switching in an optofluidic polydimethylsiloxane: Liquid crystal grating defined by cast-molding", Appl. Phys. Lett. 96, 131112 (2010). CrossRef W. Zheng, L. Yang, M. Lee, "Vertical Alignment of Liquid Crytals on Polydimethylsiloxane Thin Films", Phot. Lett. Poland 3(1), 8 (2011). CrossRef Y. Saad, Iterative methods for sparse linear systems (SIAM, 2003). CrossRef F. Schneider, J. Draheim, R. Kamberger, U. Wallrabe, "Process and material properties of polydimethylsiloxane (PDMS) for Optical MEMS", Sensors Actuat. A: Physical 151, 95 (2009). CrossRef R. Asquini, A. d'Alessandro, "BPM Analysis of an Integrated Optical Switch using Polymeric Optical Waveguides and SSFLC at 1.55 ?m", Mol. Cryst. Liquid Cryst. 375, 243 (2002). CrossRef R. Asquini, L. Civita, L. Martini, A. d'Alessandro, "Design of Optical Directional Couplers Made of Polydimethysiloxane Liquid Crystal Channel Waveguides", Mol. Cryst. Liquid Cryst. 619, 12 (2015). CrossRef

scholarly journals Liquid crystal tunable claddings for polymer integrated optical waveguides

2019 ◽  
Vol 10 ◽  
pp. 2163-2170 ◽  
Author(s):  
José Manuel Otón ◽  
Manuel Caño-García ◽  
Fernando Gordo ◽  
Eva Otón ◽  
Morten Andreas Geday ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Optical Waveguides ◽  
Optical Switching ◽  
Photonic Integrated Circuits ◽  
Optical Signals ◽  
Optical Functions ◽  
Integrated Optical ◽  
Integrated Optical Waveguides ◽  
Variable Coupling

Optical waveguides in photonic integrated circuits are traditionally passive elements merely carrying optical signals from one point to another. These elements could contribute to the integrated circuit functionality if they were modulated either by variations of the core optical properties, or by using tunable claddings. In this work, the use of liquid crystals as electro-optically active claddings for driving integrated waveguides has been explored. Tunable waveguides have been modeled and fabricated using polymers. Optical functions such as variable coupling and optical switching have been demonstrated.

scholarly journals Polymer selective laser curing for integrated optical switches

2017 ◽  
Vol 9 (1) ◽  
pp. 32
Author(s):  
Manuel Gil-Valverde ◽  
Manuel Cano-García ◽  
Rodrigo Delgado ◽  
Tianyi Zuo ◽  
José Manuel Otón ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optical Switching ◽  
Optical Switch ◽  
Single Mode ◽  
Multimode Waveguide ◽  
Direct Writing ◽  
Isotropic Liquid ◽  
Direct Laser ◽  
Laser Curing

A simple in-layer electro optical switch has been prepared by selectively curing a photocurable optical polymer with a UV laser. The core of the device is a NOA-81 multimode waveguide grown by selective laser curing. The cladding is a positive calamitic liquid crystal, which allows tunability and switching of the waveguide by external driving electric signals. The effective refractive index in the guide changes upon switching the liquid crystal. Depending on the geometry, this setup leads to an electrooptical modulator or a switch between two levels of transmitted light. Full Text: PDF ReferencesT. Ako, A. Hope, T. Nguyen, A. Mitchell, W. Bogaerts, K. Neyts, and J. Beeckman, "Electrically tuneable lateral leakage loss in liquid crystal clad shallow-etched silicon waveguides", Opt. Express 23, 2846 (2015). CrossRef K. Kruse, C. Middlebrook, "Laser-direct writing of single mode and multi-mode polymer step index waveguide structures for optical backplanes and interconnection assemblies", Photon. Nanostruct. - Fundamentals and Appl. 13, 66 (2015). CrossRef A. Günther, A.B. Petermann, M. Rezem, M. Rahlves, M. Wollweber, and B. Roth, European Conf. Lasers and Electro-Optics - European Quantum Electronics Conference, Munich, Germany (2015).C. Florian, S. Piazza, A. Diaspro, P. Serra, M. Duocastella, "Direct Laser Printing of Tailored Polymeric Microlenses", ACS Appl. Mater. Interfaces, 8(27), 17028 (2016). CrossRef F. Costache, M. Blasl, "Optical switching with isotropic liquid crystals", Opt. Photonik 6, 29 (2011). CrossRef M. Cano-Garcia, R. Delgado, T. Zuo, M.A. Geday, X. Quintana, Jose M. Otón, 16th OLC Topical Meeting on the Optics of Liquid Crystals, Sopot, Poland (2015).S. Ishihara, H. Wakemoto, K. Nakazima, Y. Matsuo, "The effect of rubbed polymer films on the liquid crystal alignment", Liq. Cryst. 4(6), 669 (1989). DirectLink

OPTICAL SWITCHING AND CONTROLLED SELF DIFFRACTION WITH POLYMER DISPERSED LIQUID CRYSTALS

1993 ◽  
Vol 02 (03) ◽  
pp. 353-365 ◽  
Author(s):  
F. SIMONI ◽  
F. BLOISI ◽  
L. VICARI
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optical Switching ◽  
Optical Switch ◽  
Wave Mixing ◽  
Switching Effect ◽  
Threshold Behavior ◽  
External Voltage ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed

Self-transparency due to thermal nonlinearities is presented as basic switching effect in polymer dispersed liquid crystals. The main consequences of this phenomenon on wave mixing are opto-optical switch and self-diffraction with threshold, How this threshold behavior can be exploited to drive self-diffraction by an external voltage applied to the sample, coupling in an original way thermal nonlinearities of the liquid crystal with its orientational properties is explained here. The possibility of obtaining a transient amplitude grating in these materials is also discussed.

Photonic Crystal Fabry-Perot Self-Collimation Interferometer by Liquid Crystal Infiltration

2010 ◽  
Vol 428-429 ◽  
pp. 573-578
Author(s):  
Guo Zhong Lai ◽  
Xi Yao Chen ◽  
Yu Fei Wang ◽  
Hong Lin
Keyword(s):  
Liquid Crystal ◽  
Photonic Crystal ◽  
Integrated Circuits ◽  
Optical Switch ◽  
Resonant Cavity ◽  
Fabry Perot ◽  
Resonant Transmission ◽  
Calculation Results ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

A Fabry-Perot self-collimation interferometer (FPSI) constructed in a two-dimensional photonic crystal (2D PhC) by liquid crystal infiltration has been proposed and demonstrated theoretically. The resonant cavity of FPSI is infiltrated with a nematic liquid crystal (LC) 5CB with ordinary and extraordinary refractive indices 1.522 and 1.706, respectively. The transmission spectrum of the FPSI has been investigated with the 2D finite-difference time-domain method. Calculation results show that resonant transmission peaks have nearly equal frequency spacing 0.0090c/a. When the effective refractive index neff of the liquid crystal is increased from 1.522 to 1.706, the peaks shift to the lower frequencies over 0.0071c/a while the peak spacing is almost kept unchanged. Thus this FPSI by LC infiltration can work as a tunable attenuator or an optical switch. For the central operating wavelength around 1.55m, its dimensions are only about tens of microns. Thus this device may be applied to photonic integrated circuits.

scholarly journals Compact Modelling of Electrical, Optical and Thermal Properties of Multi-Colour Power LEDs Operating on a Common PCB

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1286
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak
Keyword(s):  
Integrated Circuits ◽  
Optical Model ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Junction Temperature ◽  
Optical Parameters ◽  
Spice Simulation ◽  
Light Emitting ◽  
Proposed Model ◽  
Good Agreement

This paper concerns the problem of modelling electrical, thermal and optical properties of multi-colour power light-emitting diodes (LEDs) situated on a common PCB (Printed Circuit Board). A new form of electro-thermo-optical model of such power LEDs is proposed in the form of a subcircuit for SPICE (Simulation Program with Integrated Circuits Emphasis). With the use of this model, the currents and voltages of the considered devices, their junction temperature and selected radiometric parameters can be calculated, taking into account self-heating phenomena in each LED and mutual thermal couplings between each pair of the considered devices. The form of the formulated model is described, and a manner of parameter estimation is also proposed. The correctness and usefulness of the proposed model are verified experimentally for six power LEDs emitting light of different colours and mounted on an experimental PCB prepared by the producer of the investigated devices. Verification was performed for the investigated diodes operating alone and together. Good agreement between the results of measurements and computations was obtained. It was also proved that the main thermal and optical parameters of the investigated LEDs depend on a dominant wavelength of the emitted light.

A robust and inexpensive all optical switch with chiral nematic liquid crystal

2021 ◽  
Vol 119 ◽  
pp. 111306
Author(s):  
Hossein mehrzad ◽  
Ezeddin Mohajerani ◽  
Mohammad Mohammadimasoudi ◽  
Kristiaan Neyts
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Optical Switch ◽  
Chiral Nematic ◽  
All Optical ◽  
All Optical Switch

scholarly journals Design of Tunable Holographic Liquid Crystalline Diffraction Gratings

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6789
Author(s):  
Katarzyna A. Rutkowska ◽  
Anna Kozanecka-Szmigiel
Keyword(s):  
Liquid Crystal ◽  
Communication Networks ◽  
Optical Communication ◽  
Liquid Crystalline ◽  
Incident Light ◽  
Diffraction Gratings ◽  
Lagrange Equations ◽  
Experimental Conditions ◽  
Molecular Distribution ◽  
Polarization Gratings

Tunable diffraction gratings and phase filters are important functional devices in optical communication and sensing systems. Polarization gratings, in particular, capable of redirecting an incident light beam completely into the first diffraction orders may be successfully fabricated in liquid crystalline cells assembled from substrates coated with uniform transparent electrodes and orienting layers that force a specific molecular distribution. In this work, the diffraction properties of liquid crystal (LC) cells characterized by a continually rotating cycloidal director pattern at the cell substrates and in the bulk, are studied theoretically by solving a relevant set of the Euler-Lagrange equations. The electric tunability of the gratings is analyzed by estimating the changes in liquid crystalline molecular distribution and thus in effective birefringence, as a function of external voltage. To the best of our knowledge, such detailed numerical calculations have not been presented so far for liquid crystal polarization gratings showing a cycloidal director pattern. Our theoretical predictions may be easily achieved in experimental conditions when exploiting, for example, photo-orienting material, to induce a permanent LC alignment with high spatial resolution. The proposed design may be for example, used as a tunable passband filter with adjustable bandwidths, thus allowing for potential applications in optical spectroscopy, optical communication networks, remote sensing and beyond.

Improved dielectric and electro-optical parameters of ZnO nano-particle (8% Cu2+) doped nematic liquid crystal

2013 ◽  
Vol 1035 ◽  
pp. 371-377 ◽  
Author(s):  
Pankaj Kr. Tripathi ◽  
Abhishek Kr. Misra ◽  
Shashwati Manohar ◽  
Swadesh Kr. Gupta ◽  
Rajiv Manohar
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Optical Parameters ◽  
Nano Particle ◽  
Zno Nano Particle
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