scholarly journals Strong quadratic acousto-optic coupling in 1D multilayer phoxonic crystal cavity

2021 ◽  
Vol 10 (1) ◽  
pp. 443-452
Author(s):  
Jun Jin ◽  
Xiaohong Wang ◽  
Lamin Zhan ◽  
Hongping Hu
Keyword(s):  
Perturbation Theory ◽  
Born Approximation ◽  
Defect Mode ◽  
Defect Layer ◽  
Acoustic Mode ◽  
Combination Method ◽  
Moving Interface ◽  
Optical Modes ◽  
Order Of Magnitude ◽  
Quadratic Coupling

Abstract Four methods are applied to calculate the acousto-optic (AO) coupling in one-dimensional (1D) phoxonic crystal (PXC) cavity: transfer matrix method (TMM), finite element method (FEM), perturbation theory, and Born approximation. Two types of mechanisms, the photoelastic effect (PE) and the moving interface effect (MI), are investigated. Whether the AO coupling belongs to linear or quadratic, the results obtained by the perturbation theory are in good agreement with the numerical results. We show that the combination method of FEM and perturbation theory has some advantages over Born approximation. The dependence of linear and quadratic couplings on the symmetry of acoustic and optical modes has been discussed in detail. The linear coupling will vanish if the defect acoustic mode is even symmetry, but the quadratic effect may be enhanced. Based on second-order perturbation theory, the contribution of each optical eigenfrequency to quadratic coupling is clarified. Finally, the quadratic coupling is greatly enhanced by tuning the thickness of the defect layer, which is an order of magnitude larger than that of normal defect thickness. The enhancement mechanism of quadratic coupling is illustrated. The symmetry of the acoustic defect mode is transformed from odd to even, and two optical defect modes are modulated to be quasi-degenerated modes. This study opens up a possibility to achieve tunable phoxonic crystals on the basis of nonlinear AO effects.

Electro-Tunable Defect Mode in One-Dimensional Periodic Structure Containing Nematic Liquid Crystal as a Defect Layer

2002 ◽  
Vol 41 (Part 2, No. 12B) ◽  
pp. L1482-L1484 ◽  
Author(s):  
Ryotaro Ozaki ◽  
Tatsunosuke Matsui ◽  
Masanori Ozaki ◽  
Katsumi Yoshino
Keyword(s):  
Liquid Crystal ◽  
Periodic Structure ◽  
Nematic Liquid Crystal ◽  
Defect Mode ◽  
Defect Layer ◽  
One Dimensional

scholarly journals Ray perturbation theory and the Born approximation

1990 ◽  
Vol 100 (3) ◽  
pp. 379-392 ◽  
Author(s):  
R. T. Coates ◽  
C. H. Chapman
Keyword(s):  
Perturbation Theory ◽  
Born Approximation

High tunability and sensitivity of 1D topological photonic crystal heterostructure

2021 ◽  
Author(s):  
Sayed Elshahat ◽  
Zain Elabdeen A. Mohamed ◽  
Mohamed Almokhtar ◽  
Cuicui Lu
Keyword(s):  
Photonic Crystal ◽  
Defect Mode ◽  
High Sensitivity ◽  
Edge State ◽  
Defect Layer ◽  
Glucose Sensing ◽  
Photonic Sensor ◽  
High Tunability ◽  
Interface Layers ◽  
Quality Factor Q

Abstract A modality to high tunability and sensing performance of one-dimensional (1D) topological photonic crystal (PC) heterostructure is realized based on a new mechanism through 1D topological PC. With inserting a defect aqueous layer as a sandwich between two 1D PCs, the transmittance gradually decreases with the increasing thickness of the defect layer. When the two layers of the topological heterostructure interface are replaced by the defect layer, the tunability, all sensing capabilities have been improved and the principle of topology is preserved. A topologically protected edge state is formed at the heterostructure interface with a highly localized electric field. For glucose sensing, high sensitivity S = 603.753 nm/RIU is obtained at the low detection limit of about DL = 1.22×10^(-4) RIU with high-quality factor Q = 2.33×10^4 and a high figure of merit FOM = 8147.814 RIU^(-1). Besides, the transmittance can be maintained more than 99% at low and/or high glucose concentrations, due to the coupling topological edge mode between defect mode and topological edge state. An excellent platform is examined for the design of a topological photonic sensor which is a flexible platform that can be used for any type of sensor solely by replacing the interface layers with the sensor materials. Thus, our results will promote the development of 1D topological photonic devices.

scholarly journals CHOLESTERIC LIQUID CRYSTALS WITH TUNABLE DEFECT INSIDE

2011 ◽  
Vol 25 (18) ◽  
pp. 1511-1520 ◽  
Author(s):  
A. H. GEVORGYAN ◽  
K. B. OGANESYAN ◽  
E. M. HARUTYUNYAN ◽  
S. H. HARUTYUNYAN ◽  
E. A. SANTROSYAN
Keyword(s):  
Liquid Crystals ◽  
Layer Thickness ◽  
Defect Mode ◽  
Defect Layer ◽  
Refraction Coefficient ◽  
Cholesteric Liquid Crystals ◽  
Defect Modes ◽  
Defect Location ◽  
Layer Position

Peculiarities of the defect modes of cholesteric liquid crystals (CLCs) with an isotropic/anisotropic defect inside are investigated. The influence of the defect layer thickness and its anisotropy of refraction, the influence of the system thickness and of the defect layer position in the system, as well as the influence of the dielectric borders on the defect modes are investigated. It is shown that it is possible to change reflection at the defect modes in wide intervals and change the defect mode wavelength, by tuning the defect location and its thickness. Such a system possesses transmission asymmetry. Also, the CLC system thickness and the refraction coefficient of the medium bordering the CLC layer on its both sides have essential influence on the reflection at the defect mode and on the reflection frequency.

scholarly journals Coupling of Defect Modes in Cholesteric Liquid Crystals Separated by Isotropic Polymeric Layers

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 805 ◽  
Author(s):  
Shaohua Gao ◽  
Yanzi Zhai ◽  
Xinzheng Zhang ◽  
Xiao Song ◽  
Jiayi Wang ◽  
...  
Keyword(s):  
Photonic Band Gap ◽  
Cholesteric Liquid Crystal ◽  
Tight Binding ◽  
Defect Layer ◽  
Solid State Physics ◽  
Tight Binding Approximation ◽  
Defect Modes ◽  
Optical Modes ◽  
Low Threshold ◽  
Photonic Band

Cholesteric liquid crystal structures with multiple isotropic defect layers exhibit localized optical modes (defect modes). Coupling effects between these modes were simulated using the finite difference time domain method. Analogous to the well-known result of the tight-binding approximation in solid state physics, splitting of the defect modes takes place, as soon as the structure contains more than one defect layer. The dispersion relation of the mini-bands forming within the photonic band gap of the structure is calculated numerically. The structures might have promising applications for multiwavelength filters and low-threshold lasers.

scholarly journals Two-dimensional array of iron-garnet nanocylinders supporting localized and lattice modes for the broadband boosted magneto-optics

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Polina E. Zimnyakova ◽  
Daria O. Ignatyeva ◽  
Dolendra Karki ◽  
Andrey A. Voronov ◽  
Alexander N. Shaposhnikov ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Magnetic Film ◽  
Two Dimensional ◽  
Simultaneous Excitation ◽  
Optical Effects ◽  
Fabry Perot ◽  
Optical Modes ◽  
Order Of Magnitude ◽  
Iron Garnet ◽  
Dielectric Structures

Abstract We demonstrate a novel all-dielectric magnetophotonic structure that consists of two-dimensional arrays of bismuth substituted iron-garnet nanocylinders supporting both localized (Fabry–Perot-like) and lattice (guided-like) optical modes. Simultaneous excitation of the two kinds of modes provides a significant enhancement of the Faraday effect by 3 times and transverse magneto-optical Kerr effect by an order of magnitude compared to the smooth magnetic film of the same effective thickness. Both magneto-optical effects are boosted in wide spectral and angular ranges making the nanocylinder array magnetic dielectric structures promising for applications with short and tightly focused laser pulses.

Sign in / Sign up

Export Citation Format

Share Document