Active beam steering and afocal zooming by nematic liquid crystal-infiltrated graded index photonic structures
| Autor: | Ceren Babayigit, Mirbek Turduev, Hamza Kurt |
|---|---|
| Přispěvatelé: | TOBB ETU, Faculty of Engineering, Department of Electrical & Electronics Engineering, TOBB ETÜ, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Kurt, Hamza |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Acoustics and Ultrasonics Beam steering FOS: Physical sciences Physics::Optics Applied Physics (physics.app-ph) 02 engineering and technology Refractive index profile 01 natural sciences Physics Applied 010309 optics Photonic crystals 020210 optoelectronics & photonics Optics 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Focal length Photonic crystal nematic liquid crystals Afocal photography business.industry Physics Physics - Applied Physics Condensed Matter Physics Ray afocal zooming Surfaces Coatings and Films Electronic Optical and Magnetic Materials beam-steering active or adaptive optics Photonics business Refractive index graded index optics Physics - Optics Optics (physics.optics) |
| Zdroj: | Web of Science |
| Popis: | This study presents active beam steering and afocal zooming of light by incorporating liquid crystals (LCs) with graded index photonic crystal (GRIN PC). The GRIN PC structures are composed of low refractive index polymer annular rods having gradually varied radii of holes. To actively manipulate incident light, the annular rods are infiltrated with nematic LCs. By applying an external voltage to the infiltrated LCs, the effective index profile of the low-index GRIN PC structure is modulated without introducing any mechanical movement. The incident beam deflection and corresponding focal distance modulation are tuned only by controlling the applied bias voltage. In the present work, hyperbolic secant refractive index profile is chosen to design GRIN PC structures. To design GRIN PC structure with annular PCs, Maxwell-Garnett effective medium approximation is employed. Moreover, we analytically express the relation between infiltrated LCs and gradient parameter to show the physical background of the tuning ability of the proposed devices. Also, beam steering and afocal zooming devices are analytically investigated via geometrical optics and numerically realized with the help of the finite-difference time-domain method. A beam deflection with an angle change of {\Delta}{\theta}out= 44{\deg} and a light magnification with maximum x2.15 are obtained. LCs are inexpensive materials and work under low voltage/power condition. This feature can be used for designing an electro-optic GRIN PC device that can be useful in various optical applications. Comment: 13 pages, 6 figures |
| Databáze: | OpenAIRE |
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