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.

Optically isotropic liquid crystal media formulated by doping star-shaped cyclic oligosiloxane liquid crystal surfactants in twin nematic liquid crystals

Soft Matter ◽  
2015 ◽  
Vol 11 (19) ◽  
pp. 3772-3779 ◽  
Author(s):  
Namil Kim ◽  
Dae-Yoon Kim ◽  
Minwook Park ◽  
Yu-Jin Choi ◽  
Soeun Kim ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Isotropic Liquid

The formation of an optically isotropic liquid crystal (LC) medium by doping the star-shaped LC molecular surfactant in a nematic LC medium may allow us to develop new electro-optical LC devices.

Simulation of cross-talk reduction in multimode waveguide-based micro-optical switching systems by use of single-mode filters

2004 ◽  
Vol 43 (6) ◽  
pp. 1390 ◽  
Author(s):  
Tetsuzo Yoshimura ◽  
Masanori Ojima ◽  
Yukihiko Arai ◽  
Nobuhiro Fujimoto ◽  
Kunihiko Asama
Keyword(s):  
Cross Talk ◽  
Optical Switching ◽  
Single Mode ◽  
Multimode Waveguide ◽  
Switching Systems

Investigations on Integrated Optical Interference Couplers in PMMA for Visible and Infrared Range Fabricated by “Direct Writing” Excimer Laser Radiation

2019 ◽  
Vol 40 (2) ◽  
pp. 149-160
Author(s):  
Humza Mirza ◽  
Bin Wu ◽  
Sabine Tiedeken ◽  
Volker Braun ◽  
Hans Josef Brückner ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Excimer Laser ◽  
Optical Waveguides ◽  
Near Field ◽  
Single Mode ◽  
Structure Design ◽  
Infrared Range ◽  
Direct Writing ◽  
Direct Laser ◽  
Excimer Laser Radiation

Abstract Optical waveguides were generated in Polymethylmethacrylate using “direct” laser and contact mask structuring. Excimer laser radiation (248 nm) produced a local refractive index increase thereby achieving light guiding in waveguides with widths from 2 to 15 $\mu$m. The near field output images were analyzed using visible and infrared laser light. The mode fields of single mode structures were evaluated to elaborate numerically the parameters of the index profile. An index increase up to 0.01 could be achieved using laser pulses at fluences below $0.15$ ${\textrm{J/cm}^{2}}$. Thus it was possible to design interference couplers of 5 $\mu$m waveguides width for the visible (635 nm to 670 nm) as well as for the infrared range at 1550 nm. The coupling properties as a function of the waveguide separation and the wavelength is investigated and found compatible with numerical simulations for the structure design. The presented approach allows for designing and fabricating single mode couplers in an efficient and simple manner.

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 Crystals Investigation Behavior on Azo-Based Compounds: A Review

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3462
Author(s):  
Nurul Asma Razali ◽  
Zuhair Jamain
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Intermediate Phase ◽  
Crystalline Solid ◽  
Structure Property ◽  
Isotropic Liquid ◽  
Daily Lives ◽  
Spacer Length ◽  
Ideal System ◽  
Electron Withdrawing Group

Liquid crystal is an intermediate phase between the crystalline solid and an isotropic liquid, a very common substance in our daily lives. Two major classes of liquid crystal are lyotropic, where a liquid crystal is dissolved in a specific solvent under a particular concentration and thermotropic, which can be observed under temperature difference. This review aims to understand how a structure of a certain azo compound might influence the liquid crystal properties. A few factors influence the formation of different liquid crystals: the length of the alkyl terminal chain, inter/intra-molecular interaction, presence of spacer, spacer length, polarization effects, odd-even effects, and the presence of an electron-withdrawing group or an electron-donating group. As final observations, we show the compound’s different factors, the other liquid crystal is exhibited, and the structure–property relationship is explained. Liquid crystal technology is an ideal system to be applied to products to maximize their use, especially in the electronic and medical areas.

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