scholarly journals Band Structure Engineering in 2D Photonic Crystal Waveguide with Rhombic Cross-Section Elements

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Abdolrasoul Gharaati ◽  
Sayed Hasan Zahraei

Two-dimensional photonic crystal (2D PhC) waveguides with square lattice composed of dielectric rhombic cross-section elements in air background, by using plane wave expansion (PWE) method, are investigated. In order to study the change of photonic band gap (PBG) by changing of elongation of elements, the band structure of the used structure is plotted. We observe that the size of the PBG changes by variation of elongation of elements, but there is no any change in the magnitude of defect modes. However, the used structure does not have any TE defect modes but it has TM defect mode for any angle of elongation. So, the used structure can be used as optical polarizer.

2015 ◽  
Vol 29 (22) ◽  
pp. 1550159 ◽  
Author(s):  
Jian-Xia Hu ◽  
Yun-Tuan Fang

In order to obtain tunable surface modes of photonic crystal, we add a magnetic material layer on the truncated surface of a two-dimensional photonic crystal. Through calculations of photonic band, we obtain the surface defect modes in the first and second gaps. Through the modulation of applied magnetic field, we can control the frequency, the group velocity and the exciting incidence direction of the surface defect mode. In particular, in the frequency range of surface defect modes, we can tune the group velocity to zero.


2011 ◽  
Author(s):  
Xuan Guo ◽  
Lihong Han ◽  
Guifang Yuan ◽  
Zhongyuan Yu ◽  
Yumin Liu ◽  
...  

2020 ◽  
Vol 41 (4) ◽  
pp. 355-361
Author(s):  
Vahid Fallahi ◽  
Mahmood Seifouri

AbstractIn this article, a 2D photonic crystal (PC)-based optical filter has been designed using a PC ring resonator. The resonator used is of square type with a square lattice constant, which has been designed by increasing the radius of the inner rods of the resonator. The filter designed can separate the light of the wavelength of 1545.3 nm with a transmission coefficient of 98 %. The bandwidth of the above wavelength is equal to 0.5 nm and hence the quality factor of the device at this wavelength is equal to 3091. The effects of the structural parameters, such as the refractive index, the lattice constant, the radius of the dielectric rods, the radius of the inner rods of the resonator on the behavior of the proposed device, are fully investigated. To obtain the photonic band gap, the plane wave expansion method is used. In addition, the finite difference time domain method is used to examine, simulate, and to obtain the output spectrum of the structure. The designed structure has both high transmission coefficient and quality factor. Comparatively speaking, it is also simple to design which justifies its use in other photonic crystal-based optical devices.


2015 ◽  
Vol 24 (03) ◽  
pp. 1550027 ◽  
Author(s):  
G. Rajalakshmi ◽  
A. Sivanantha Raja ◽  
D. Shanmuga Sundar

In this paper, the channel drop filter based on two dimensional photonic crystal is proposed. The structure is made of silicon rods with the refractive index n1 = 3.4641 which are perforated in air with refractive index n2 = 1. The simulation results are obtained using 2D finite difference time domain (FDTD) method. The photonic band gap is calculated by plane wave expansion solver method. Resonant mode of the ring resonator and the filter transmission spectrum is calculated using 2D FDTD method. Full width half maximum (FWHM) bandwidth of the filter at the output transmission spectrum from 1.508 μm to 1.512 μm is 4 nm. The quality factor of the filter is 377.5 and the proposed filter design is around 21 × 15 μm which is suitable for photonic integrated circuits.


2012 ◽  
Vol 529 ◽  
pp. 14-18
Author(s):  
Pei Liu ◽  
Xiao Song Zhang ◽  
Chuan Zhen Xin ◽  
Meng Zhen Li ◽  
Lan Li

In this research, a triangular two-dimensional (2D) photonic crystal (PC) was hypothetically introduced into the active layer of a PbS quantum dots (QDs) electroluminescent (EL) device. The attributes of the photonic band gap effect and diffraction effect were considered and evaluated for device performance improvement. We designed and optimized the 2D-PC structure parameters to enhance the emission intensity at wavelength 1124 nm. The optimal structure parameter of PC is determined by normalized radius of r/a=0.49 and lattice constant of a=540 nm when the thickness of PC slab h is 74 nm. The 3D stimulation view of light propagation validates and supports the proposed strategy. The results provide a theoretical prediction for ideal PbS QDs-based EL device.


2014 ◽  
Vol 1035 ◽  
pp. 437-441
Author(s):  
Jin Xia Gao ◽  
Ji Jiang Wu

One-dimensional dielectric photonic crystals (PCs) with complex substitutional defect layers, consisting of superconducting (SC) and dielectric sublayers are theoretically studied. The influence of the incidence angle on the photonic gap spectra is theoretically analyzed. The pronounced difference in the transmittivity spectra of the PCs with right-handed (RH) and left-handed (LH) positions of the superconducting defect sublayer with respect to the dielectric defect sublayer is demonstrated. It is observed that, for the case of RH SC defect sublayer, the position of the defect mode and the transmittivity at the defect mode frequency strongly depend on the thickness of the superconducting sublayer as well as on the temperature. But the defect modes of the PCs with LH SC defect sublayer are nearly invariant upon the change of the thickness of the superconducting sublayer and the temperature.


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