scholarly journals Super Strong Wide TM Mie Bandgaps Tolerating Disorders

2021 ◽  
Author(s):  
Kiyanoush Goudarzi ◽  
Moonjoo Lee
Keyword(s):  
Refractive Index ◽  
Integrated Circuits ◽  
Polarized Light ◽  
High Refractive Index ◽  
Transverse Magnetic ◽  
Optical Integrated Circuits ◽  
Light Waves ◽  
High Efficient ◽  
Lower Refractive Index ◽  
Silicon And Germanium

Abstract This study demonstrates the appearance of super intense and wide Mie bandgaps in metamaterials composed of germanium rods in air that tolerate some disordering of rod position and rod radius under transverse magnetic (TM) polarized light waves. Results for Mie bandgap modes TM01 and TM11 tolerate rod-position disordering of 50%, and rod-radius disordering of 34 and 20%, respectively. Using these characteristics of TM11 under position and radius disordering, ultra-narrow straight, L-shaped and crossing waveguides that contain 14, four, and two rows of Ge rods in air are designed. Also, it is shown that TE01 Mie bandgap appear in metamaterials contain high refractive index, and disappear in metamaterials with lower refractive index such as silicon; in contrast, a new phenomenon of intense and broadband TM01, TM11, and TM21 in metamaterials with lower refractive index such as silicon appear. Also, in Si-based metamaterials, TM01 tolerates high rod-position and rod-radius disordering of 50% and 34%, respectively, and TM11 shows robustness to rod-position and rod-radius of 20%. This strong tolerance of disordering of TM modes in silicon and germanium metamaterials opens a new way to design small, high-efficient, and easy-fabricable optical devices for optical integrated circuits.

Light microscopy of ceramics

1993 ◽  
Vol 51 ◽  
pp. 908-909
Author(s):  
Walter C. McCrone
Keyword(s):  
Refractive Index ◽  
Light Microscopy ◽  
Light Microscope ◽  
Polarized Light ◽  
Refractive Indices ◽  
Complete Coverage ◽  
The Subject ◽  
Lower Refractive Index

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).

scholarly journals Fano Resonance in an Asymmetric MIM Waveguide Structure and Its Application in a Refractive Index Nanosensor

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 791 ◽  
Author(s):  
Mengmeng Wang ◽  
Meng Zhang ◽  
Yifei Wang ◽  
Ruijuan Zhao ◽  
Shubin Yan
Keyword(s):  
Refractive Index ◽  
Integrated Circuits ◽  
Fano Resonance ◽  
Structural Parameters ◽  
High Sensitivity ◽  
Split Ring Resonator ◽  
Peak Position ◽  
Optical Integrated Circuits ◽  
Metal Insulator Metal ◽  
Calculation Results

Herein, the design for a tunable plasmonic refractive index nanosensor is presented. The sensor is composed of a metal–insulator–metal waveguide with a baffle and a circular split-ring resonator cavity. Analysis of transmission characteristics of the sensor structures was performed using the finite element method, and the influence of the structure parameters on the sensing characteristics of the sensor is studied in detail. The calculation results show that the structure can realize dual Fano resonance, and the structural parameters of the sensor have different effects on Fano resonance. The peak position and the line shape of the resonance can be adjusted by altering the sensitive parameters. The maximum value of structural sensitivity was found to be 1114.3 nm/RIU, with a figure of merit of 55.71. The results indicate that the proposed structure can be applied to optical integrated circuits, particularly in high sensitivity nanosensors.

Investigative Study of Optical Parameters of Se80.5Bi1.5Te18-yAgy Thin Films

2012 ◽  
Vol 710 ◽  
pp. 739-744 ◽  
Author(s):  
Anup Kumar ◽  
Pawan Heera ◽  
P. B Baraman ◽  
Raman Sharma
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Integrated Circuits ◽  
Band Gap ◽  
Communication Systems ◽  
Optical Band Gap ◽  
Optical Parameters ◽  
Optical Integrated Circuits ◽  
Increase With Increase ◽  
Good Transparency

The optical constants, like absorption coefficient (α), optical band gap (Eg) and refractive index (n), in Se80.5Bi1.5Te18-yAgy (y= 0, 1.0 and1.5) thin films are calculated using well known Swanepoel’s method in the spectral range of 600-2000 nm. The optical band gap has been estimated by using Tauc’s extrapolation method and is found to increase with increase in Ag content. The present results shows that the large value of nonlinear refractive index and good transparency of these thin films will make them a very promising materials for optical integrated circuits in the optical communication systems.

SiO2 and TiO2 Sol-Gel Blends with Tunable Optical and Electronic Properties

MRS Advances ◽  
2019 ◽  
Vol 4 (11-12) ◽  
pp. 689-695
Author(s):  
Stephanie Arouh ◽  
Roland Himmelhuber ◽  
Robert A. Norwood
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Initial Mixture ◽  
High Refractive Index ◽  
Dielectric Constants ◽  
Glass Substrates ◽  
Optical And Electronic Properties ◽  
Tio2 Sol ◽  
Coating Method ◽  
Lower Refractive Index

Sol-gel blends are created using a combination of a high refractive index (n∼2.4) TiO2 based sol-gel and a low refractive index (n∼1.5) SiO2 based sol-gel. The blends are prepared with different ratios of sol-gels and films are created using the spin coating method on silicon and ITO-on-glass substrates. The film thickness, refractive index, and dielectric constants of the resulting films are measured using profilometry, prism coupling, and LCR measurements, respectively. Results show that including more SiO2 based sol-gel in the initial mixture creates thicker films ranging from 1-7 μm, but results in lower refractive index and lower dielectric constants. This is consistent with expectations due to SiO2 having a lower refractive index and dielectric constant than titania over a range of wavelengths andfrequencies. The ability to fine tune the properties is explored.

scholarly journals A compact plasmonic MOS-based 2×2 electro-optic switch

Nanophotonics ◽  
2015 ◽  
Vol 4 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Chenran Ye ◽  
Ke Liu ◽  
Richard A. Soref ◽  
Volker J. Sorger
Keyword(s):  
Integrated Circuits ◽  
Indium Tin Oxide ◽  
Low Cost ◽  
Extinction Ratio ◽  
Polarized Light ◽  
Transverse Magnetic ◽  
Silicon On Insulator ◽  
Oxide Semiconductor ◽  
Seamless Integration ◽  
Electro Optic

Abstract We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, indium-tin-oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with silicon-on-insulator platforms for low-cost manufacturing.

Enhancement of Afterglow Luminescence of Long-Lasting Phosphor-Glass Composite by Using Refractive Index Matched Glass

2016 ◽  
Vol 702 ◽  
pp. 113-117 ◽  
Author(s):  
Masaru Yamashita ◽  
Toshinori Imamura ◽  
Sachiko Matsumoto ◽  
Masaki Murakami ◽  
Toshiaki Hongo ◽  
...  
Keyword(s):  
Refractive Index ◽  
Glass Composition ◽  
High Refractive Index ◽  
Dark Field ◽  
Glass Composite ◽  
Thick Sample ◽  
Index Matching ◽  
Digital Microscope ◽  
Refractive Index Matching ◽  
Lower Refractive Index

Composites of a long-lasting phosphor, SrAl2O4:Eu,Dy, and glass were prepared by sintering the phosphor and glass powder. To enhance the afterglow luminescence, a borosilicate glass composition was chosen so that the refractive index of the glass matched that of the phosphor. Additional components with a high refractive index, such as La2O3 and Nb2O5, were added to the glass to increase the overall refractive index. As they tend to induce crystallization during sintering, small amounts of at least three types of such components were added to the glass to prevent crystallization. The surface of the composite was observed by a digital microscope with dark-field lighting. The phosphor particles became almost transparent because of the refractive-index matching, although bubbles were observed inside the phosphor particles. The afterglow luminance was, however, almost the same and the transmittance of the composite was not high because of many voids when compared to as that of the sample using the glass with a lower refractive index. The sample prepared under vacuum showed coloration and similar afterglow luminance even though the number of voids inside the composite decreased. To suppress the coloration, the amount of tin in the glass was increased, after which higher transparency and afterglow luminance were obtained. A 4-mm-thick sample showed a luminance of 118 mcd∙m-2 60 min after irradiation by a D65 lamp with 200 lx for 20 min.

scholarly journals All-dielectric metasurfaces for polarization manipulation: principles and emerging applications

Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3755-3780 ◽  
Author(s):  
Yueqiang Hu ◽  
Xudong Wang ◽  
Xuhao Luo ◽  
Xiangnian Ou ◽  
Ling Li ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Efficiency ◽  
High Refractive Index ◽  
Data Encryption ◽  
Optical Systems ◽  
Ohmic Loss ◽  
Imaging Data ◽  
New Paradigm ◽  
High Efficient ◽  
Low Efficiency

AbstractMetasurfaces, composed of specifically designed subwavelength units in a two-dimensional plane, offer a new paradigm to design ultracompact optical elements that show great potentials for miniaturizing optical systems. In the past few decades, metasurfaces have drawn broad interests in multidisciplinary communities owing to their capability of manipulating various parameters of the light wave with plentiful functionalities. Among them, pixelated polarization manipulation in the subwavelength scale is a distinguished ability of metasurfaces compared to traditional optical components. However, the inherent ohmic loss of plasmonic-type metasurfaces severely hinders their broad applications due to the low efficiency. Therefore, metasurfaces composed of high-refractive-index all-dielectric antennas have been proposed to achieve high-efficiency devices. Moreover, anisotropic dielectric nanostructures have been shown to support large refractive index contrast between orthogonal polarizations of light and thus provide an ideal platform for polarization manipulation. Herein, we present a review of recent progress on all-dielectric metasurfaces for polarization manipulation, including principles and emerging applications. We believe that high efficient all-dielectric metasurfaces with the unprecedented capability of the polarization control can be widely applied in areas of polarization detection and imaging, data encryption, display, optical communication and quantum optics to realize ultracompact and miniaturized optical systems.

scholarly journals Acousto-optic modulation of photonic bound state in the continuum

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Zejie Yu ◽  
Xiankai Sun
Keyword(s):  
Refractive Index ◽  
Integrated Circuits ◽  
Acoustic Waves ◽  
Bound States ◽  
Quantum Information Processing ◽  
Modulation Frequency ◽  
Surface Acoustic Waves ◽  
High Refractive Index ◽  
Bound State ◽  
The Continuum

AbstractPhotonic bound states in the continuum (BICs) have recently been studied in various systems and have found wide applications in sensors, lasers, and filters. Applying BICs in photonic integrated circuits enables low-loss light guidance and routing in low-refractive-index waveguides on high-refractive-index substrates, which opens a new avenue for integrated photonics with functional single-crystal materials. Here, we demonstrate high-quality integrated lithium niobate microcavities inside which the photonic BIC modes circulate and further modulate these BIC modes acousto-optically by using piezoelectrically actuated surface acoustic waves at microwave frequencies. With a high acousto-optic modulation frequency, the acousto-optic coupling is well situated in the resolved-sideband regime. This leads to coherent coupling between microwave and optical photons, which is exhibited by the observed electro-acousto-optically induced transparency and absorption. Therefore, our devices serve as a paradigm for manipulating and controlling photonic BICs on a chip, which will enable many other applications of photonic BICs in the areas of microwave photonics and quantum information processing.

scholarly journals Nearly total optical transmission of linearly polarized light through transparent electrode composed of GaSb monolithic high-contrast grating integrated with gold

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Landobasa Y. M. Tobing ◽  
Michał Wasiak ◽  
Dao Hua Zhang ◽  
Weijun Fan ◽  
Tomasz Czyszanowski
Keyword(s):  
Sheet Resistance ◽  
Optical Transmission ◽  
Polarized Light ◽  
High Refractive Index ◽  
Transparent Electrode ◽  
Transverse Magnetic ◽  
Electromagnetic Spectrum ◽  
Near Ultraviolet ◽  
Linearly Polarized ◽  
High Contrast Grating

Abstract Achieving high transmission of light through a highly conductive structure implemented on a semiconductor remains a challenge in optoelectronics as the transmission is inevitably deteriorated by absorption and Fresnel reflection. There have been numerous efforts to design structures with near-unity transmission, yet they are typically constrained by a trade-off between conductivity and optical transmission. To address this problem, we propose and demonstrate a transmission mechanism enabled by a monolithic GaSb subwavelength grating integrated with Au stripes (metalMHCG). Near-unity transmission of polarized light is achieved by inducing low-quality factor resonance in the air gaps between the semiconductor grating stripes, which eliminates light absorption and reflection by the metal. Our numerical simulation shows 97% transmission of transverse magnetic polarized light and sheet resistance of 2.2 ΩSq−1. The metalMHCG structure was realized via multiple nanopatterning and dry etching, with the largest transmission yet reported of ∼90% at a wavelength of 4.5 µm and above 75% transmission in the wavelength range from 4 to 10 µm and sheet resistance at the level of 26 ΩSq−1. High optical transmission is readily achievable using any high refractive index materials employed in optoelectronics. The design of the metalMHCG is applicable in a wide electromagnetic spectrum from near ultraviolet to infrared.

scholarly journals Design and Simulation of a Very Fast and Compact All-Optical Full-Subtractor Based an Nonlinear Effect in 2D Photonic Crystals

2021 ◽  
Author(s):  
Reza Beiranvand ◽  
Ali Mir ◽  
Reza Talebzadeh
Keyword(s):  
Refractive Index ◽  
Photonic Crystals ◽  
Integrated Circuits ◽  
Square Lattice ◽  
Optical Integrated Circuits ◽  
All Optical ◽  
Non Linear ◽  
Linear Material ◽  
Silicon Rods ◽  
Doped Glass

Abstract In this paper, by using the non-linear effects and also destructive and constructive interferences between waveguides, we have designed and simulated an all-optical full-Subtractor based on two-dimensional photonic crystals. The proposed Subtractor has a very simple structure which is composed of 33×31 silicon rods immersed in air in a square lattice and involves three input ports (bits) and an additional waveguide to exhaust the unwanted light. We imposed some defect rods to control the behavior of the light. The used non-linear material, is a doped glass with 1.4×10− 14 m2/w non-linear refractive index which is very greater than the non-linearity refractive index of silicon, 3.46×10− 20 m2/w. Since the proposed structure is very simple and compact, it can be applicable in optical integrated circuits and optical calculations.

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