scholarly journals Compact Photonic-Crystals Based Isolator Using Ni–Zn Gyromagnetic Ferrite Posts

2021 ◽  
Vol 11 (13) ◽  
pp. 6177
Author(s):  
Yong Wang ◽  
Biaogang Xu ◽  
Dengguo Zhang ◽  
Wenlong He ◽  
Hou Ian

A Faraday rotation isolator is conventionally achieved by connecting a matched load to a three-port circulator. It obtains superior performance (isolation > 20 dB) at the inevitable cost of non-ideal size. In order to adapt to the miniaturizations and integrations required for future 5G communication systems, it is particularly important to reduce the size of the devices. This work demonstrates a photonic crystal-based isolator design, comprising a unique reflecting cavity and a built-in fan-shaped coupler, where four Ni–Zn ferrite posts achieve the rotations. The design with the compact size of about 46.6 × 41.6 × 4.32 mm3 obtains excellent forward transmission efficiency and reverse isolation of 0.50 dB and 44.20 dB, respectively.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Roumaissa Derdour ◽  
Mohamed Redha Lebbal ◽  
Souheil Mouetsi ◽  
Abdesselam Hocini

Abstract A new connected structure of an all-optical “OR” logic gate realized with photonic crystals is proposed in this study. The structure is based on coupling the input guides with two microcavities; the unit cell of the structure is designed to achieve a band gap around the communication wavelength (i.e., 1.55 µm). The performance of the structure results in transmission efficiency and low losses. This compact size logic gate is considered an important element in the integration of a nanoscale photonic device.


Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 570 ◽  
Author(s):  
Yong Wang ◽  
Biaogang Xu ◽  
Dengguo Zhang ◽  
Shixiang Xu ◽  
Zheng Dong ◽  
...  

This paper presents a novel magneto-optical isolator based on an ultra-wideband and high efficiency photonic crystals (PCs) waveguide and gyromagnetic ferrites. The three-dimensional numerical simulation finds that the photonic crystals waveguide’s (PCW) transmission efficiency rises with its height and width. The corresponding experiments are performed by using a triangular lattice Al2O3 dielectric posts array in 5G millimeter wave band. The measured transmission efficiency is up to 90.78% for the optimal PCs waveguide structure, which has ultra-wide operating bandwidth from 23.45 to 31.25 GHz. The magneto-optical isolator is designed by inserting two rectangular gyromagnetic ferrites into the PCs waveguide. Due to the contrast between the effective permeability of the left and right circular polarization waves passing through the magnetized ferrite sheets, the ferromagnetic resonance absorption of the forward and reverse waves is different. By using finite element method, the isolation is optimized to be 49.49 dB for the isolator and its relative bandwidth reaches 8.85%. The high isolation, broadband, and easy integration indicate that our designed magneto-optical isolator has significant advantage in 5G communication systems.


2021 ◽  
Author(s):  
Kouddad Elhachemi ◽  
Naoum Rafah ◽  
Dekkiche Leila

Abstract In our work, we propose a novel temperature sensor design based on a two-dimensional (2D) photonic crystal resonant cavity structure designed to detect and monitor temperature under very harsh environmental conditions from 0 °C to 500 ºC. The sensitivity of the proposed structure is 109.8 pm/ºC, an ultra-high quality factor, high transmission efficiency and ultra-compact size. The characteristics of the proposed sensor under different temperatures are simulated using the Plane Wave Expansion (PWE) method and Finite Difference Time Domain (FDTD) method to calculate, respectively, the Photonic Band Gap (PBG) and transmission efficiency. The results obtained show that the wavelength of the resonant cavity increases linearly with increasing temperature. Our sensor is suitable for applications based on nanotechnology.


Frequenz ◽  
2017 ◽  
Vol 72 (1-2) ◽  
Author(s):  
Milad Taleb Hesami Azar ◽  
Hamed Alipour-Banaei ◽  
Mahdi Zavvari

AbstractIn this paper a high efficiency optical power splitter based on two-dimensional photonic crystals is proposed. The photonic crystal cavity is assumed to be constructed by TiO


2009 ◽  
Vol 129 (4) ◽  
pp. 601-607
Author(s):  
Shubi F. Kaijage ◽  
Yoshinori Namihira ◽  
Nguyen H. Hai ◽  
Feroza Begum ◽  
S. M. Abdur Razzak ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.


2012 ◽  
Vol 26 (26) ◽  
pp. 1250170 ◽  
Author(s):  
TAO CHEN ◽  
CAILONG ZHENG ◽  
JINXING LI

We present a procedure to enhance the transmission efficiency of a photonic crystal slab waveguide bend by introducing an air hole with the same radius at the center of bend and optimizing the positions of three neighboring holes in the corner. The improvement relies only on the method of displacing holes which is technologically preferred to controlling variations in hole size or shape. We employ the effective refractive index approach and two-dimensional plane wave expansion method to analyze the guide modes of the straight waveguide and waveguide bend. The transmission character of bent waveguides is investigated using two-dimensional finite-difference time-domain method. Numerical studies demonstrate that the approximate method of mode analysis is unsuitable to our model. Alternatively, we systematically study the effect of different positions of the holes on the transmission. The optimized bends for the high transmission with broad bandwidth are proposed.


Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 12969-12975 ◽  
Author(s):  
Xiang Fei ◽  
Tao Lu ◽  
Jun Ma ◽  
Shenmin Zhu ◽  
Di Zhang

Photonic crystals with both optical and thermal responses based on a natural butterfly wing template.


2013 ◽  
Vol 284-287 ◽  
pp. 2876-2879
Author(s):  
Yih Bin Lin ◽  
Jen Hao Cheng ◽  
Rei Shin Chen ◽  
Ting Chung Yu ◽  
Ju Feng Liu ◽  
...  

A novel design of photonic crystal waveguide crossing based on multimode-interference (MMI) structure is proposed. Two structures of difference device lengths are simulated and studied. The proposed structures have high transmission efficiency for a wide bandwidth. The crosstalk is -26dB with device length of 12 lattice periods and -39dB with device length of 24 lattice periods. The plane wave expansion method and finite-difference time-domain method are used to calculate the modal dispersion curve and field propagation, respectively. The proposed MMI-based waveguide crossing has the potential to be practical in high-density optical integrated circuits.


SPIN ◽  
2012 ◽  
Vol 02 (03) ◽  
pp. 1240004 ◽  
Author(s):  
NIAN X. SUN ◽  
GOPALAN SRINIVASAN

Multiferroic materials and devices have attracted intensified recent interests due to the demonstrated strong magnetoelectric (ME) coupling in new multiferroic materials and devices with unique functionalities and superior performance characteristics. Strong ME coupling has been demonstrated in a variety of multiferroic heterostructures, including bulk magnetic on ferro/piezoelectric multiferroic heterostructures, magnetic film on ferro/piezoelectric slab multiferroic heterostructures, thin film multiferroic heterostructures, etc. Different multiferroic devices have been demonstrated, which include magnetic sensors, energy harvesters, and voltage tunable multiferroic RF/microwave devices which are compact, lightweight, and power efficient. In this progress report, we cover the most recent progress on multiferroic heterostructures and devices with a focus on voltage tunable multiferroic heterostructures and devices with strong converse ME coupling. Recent progress on magnetic-field tunable RF/microwave devices are also covered, including novel non-reciprocal tunable bandpass filters with ultra wideband isolation, compact, low loss and high power handling phase shifters, etc. These novel tunable multiferroic heterostructures and devices and tunable magnetic devices provide great opportunities for next generation reconfigurable RF/microwave communication systems and radars, Spintronics, magnetic field sensing, etc.


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