scholarly journals Low Input Power an All Optical 4 × 2 Encoder based on Triangular Lattice Shape Photonic Crystal

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Naghizade ◽  
H. Khoshsima
Keyword(s):  
Photonic Crystal ◽  
Triangular Lattice ◽  
Fdtd Method ◽  
Input Power ◽  
Optical Encoder ◽  
Low Input ◽  
All Optical ◽  
Linear Effects ◽  
2D Fdtd ◽  
Transmission And Distribution

AbstractAn all optical encoder based triangular lattice shape photonic crystal (PC) is proposed. The device is composed of two ring resonator waveguides and two OR gate with four input ports waveguides and two output ports waveguides in triangular lattice shape PC. The band diagram of base PC structure calculated by plane wave expansion (PWE) method. Also, transmission and distribution of electrical field behaviors of the proposed device are verified by two dimensional finite difference time domain (2D-FDTD) method. The proposed 4 × 2 encoder can operate at third communication window range, considering definitions of logic 0 and 1 being the normalized transmission as less than 3% and greater than 95% respectively. Despite the nonlinear encoders, in our case, due to the non-use of non-linear effects such as Kerr effect, low input power required for encoder.

Design and Numerical Analysis of an All-optical 4-channel Power Splitter in E, S, C, L, and U Bands via Nano-line Defects in Photonic Crystal

2020 ◽  
Vol 41 (3) ◽  
pp. 241-247
Author(s):  
Saeed Olyaee ◽  
Mahmood Seifouri ◽  
Ebrahim Azimi Sourani ◽  
Vigneswaran Dhasarathan
Keyword(s):  
Photonic Crystal ◽  
Band Gap ◽  
Output Power ◽  
Wavelength Range ◽  
Fdtd Method ◽  
Input Power ◽  
Square Lattice ◽  
Power Splitter ◽  
All Optical ◽  
Line Defects

AbstractIn the present study, the propagation of electromagnetic waves in a square-lattice photonic crystal waveguide (PCW) is investigated using the finite-difference time-domain (FDTD) method. Then, the plane wave expansion (PWE) method is utilized to calculate the 2D photonic crystal band structure. To realize the desired waveguide, nano-line defects are introduced. The results of the numerical simulations and optimization scanning indicate that for the proposed photonic crystal structure consisting of silicon circular dielectric rods with a radius of 84 nm, a band gap can be achieved in the wavelength range of 1.34 μm<λ<1.93 μm. This wavelength range covers E, S, C, L, and U communication bands. Subsequently, by eliminating the rods in four parts of the structure, an all-optical 4-channel splitter can be designed. The numerical simulation results indicate that by coupling a light source to the main path of the structure and propagating it through each channel, the powers of the 4 output facets become approximately the same. The output power of channels 1 and 2 equals to 24.5 % of the input power, and the output power of channels 3 and 4 is 21 % of the input power and the remaining 9 % is lost in the structure as the leakage power. Since the 1.55 μm wavelength is within the band gap, that is the telecommunication band C, this device can be used as a power splitter.

Compact 2D FDTD method for modeling photonic crystal fibers

2004 ◽  
Author(s):  
Shuqin Lou ◽  
Zhi Wang ◽  
Guobin Ren ◽  
Shuisheng Jian
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fibers ◽  
Fdtd Method ◽  
Crystal Fibers ◽  
2D Fdtd

Concave Rectangle Photonic Crystal Ring Resonator for Ultra-Fast All-Optical Modulation

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Sana Rebhi ◽  
Radhouene Massoudi ◽  
Monia Najjar
Keyword(s):  
Photonic Crystal ◽  
Insertion Loss ◽  
Ring Resonator ◽  
Extinction Ratio ◽  
Input Power ◽  
Light Signal ◽  
Optical Modulator ◽  
Nonlinear Photonic Crystal ◽  
All Optical ◽  
Photonic Crystal Ring Resonator

AbstractIn this paper, an ultra-fast all-optical modulator, based on a new shape of nonlinear photonic crystal ring resonator, is designed and studied. Numerical methods such as plane wave expansion (PWE) and finite-difference time domain (FDTD) are used to perform simulations. The modulation technique consists of carrier light controlling by means of input light signal and Kerr effect. The investigation of extinction ratio and insertion loss within the carrier input power shows that the choice of 0.7 W is the optimal value of that power to ensure the tradeoff between both characteristics. The suggested modulator demonstrates an excellent extinction ratio about 20.8018, a very low insertion loss of −13.98 and a short switching time about 13.4 ps. According to the obtained results, the modulator can be considered as an ultra-fast and ultra-compact optical component.

All-Optical Switching in Ultrashort Photonic Crystal Couplers Modified Y-branch Structure

2015 ◽  
Vol 36 (3) ◽  
Author(s):  
Masoud Zahravi ◽  
Mitra Zahravi ◽  
Hamed Alipour-Banaei
Keyword(s):  
Photonic Crystal ◽  
Optical Switching ◽  
Optical Switch ◽  
Fdtd Method ◽  
Wavelength Division ◽  
All Optical ◽  
Channel Wavelength ◽  
All Optical Switch ◽  
Difference Time ◽  
All Optical Switching

AbstractIn this paper, an all-optical switch based on photonic crystal directional coupler has been simulated and analyzed by the finite difference time domain (FDTD) method. An ultra small 3-channel wavelength division demultiplexer based on 2D photonic crystal was modified into all-optical switch suitable for integration. The output wavelengths of designed structure can be tuned for communication applications (around 1.5 µm, 1.4 µm, 1.3 µm) by locating suitable defect parameters in the corner of each resonance cavity and input waveguides. The bandwidth of each channel is about 1 nm.

scholarly journals Performance Analysis of Optical AND Gate Using T- Shaped Waveguide

2021 ◽  
Author(s):  
Dalai Gowri sankar Rao ◽  
Seeta Rama Raju Karyabhattu ◽  
Sandip Swarnakar ◽  
Santosh Kumar
Keyword(s):  
Photonic Crystal ◽  
Logic Gate ◽  
Fdtd Method ◽  
Expansion Method ◽  
Ring Resonators ◽  
Transmission Ratio ◽  
Good Time ◽  
Optical Processing ◽  
Compact Size ◽  
All Optical

Abstract Ultra-compact all-optical AND logic gate is realized for optical processing and photonic integrated devices with two-dimensional photonic crystal waveguides based on beam interference principle. The performance of the structure is examined and evaluated by optimized parameters such as refractive index and silicon rod radius. The results obtained from a numerical calculation using the finite-difference time-domain (FDTD) method and plane wave expansion method. The photonic crystal based all-optical AND logic gate has benefits of compact size as 38.88 μ𝑚2, operated at low power levels, high transmission ratio and good time response as 0.124 ps. Associated with conventional semiconductor optical amplifiers, Mach-Zehnder interferometer and photonic crystal ring resonators proposed methodology provides better performance with a high achieved more than 97% transmission ratio, at a wavelength of 1.55 μm.

HIGH EFFICIENT ALL-OPTICAL DIODE ACTION THROUGH NONLINEAR FINITE ONE-DIMENSIONAL PHOTONIC CRYSTAL COATED WITH A METAL FILM

2013 ◽  
Vol 22 (03) ◽  
pp. 1350025
Author(s):  
YUN-TUAN FANG ◽  
MIN ZHU ◽  
LI-XIA YANG ◽  
XIANG ZHOU ◽  
WA KONG ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Metal Film ◽  
Light Propagation ◽  
Fdtd Method ◽  
Metal Loss ◽  
One Dimensional ◽  
Dimensional Photonic Crystal ◽  
High Efficient ◽  
All Optical ◽  
Optical Diode

Light propagation in a finite nonlinear one-dimensional photonic crystal coated with a metal film is theoretically investigated through the nonlinear transfer matrix method and the finite-difference time-domain (FDTD) method. It is found that the layered structure exhibits both pronounced unidirectionality and high transmission. This leads to all-optical diode actions. Compared with other similar studies, the designed structure has some advantages. First, the structure only with seven periods is much simpler than presented similar structures; second, the structure has both high transmittance and large transmission contrast; third, the perfect performance of AOD is robust to the metal loss.

scholarly journals Design Plasmonic Optical 4×2 Encoder based on 2D Photonic Crystal Ring Resonator

2021 ◽  
Author(s):  
samaneh hamedi ◽  
Roozbeh Negahdari ◽  
Hamid Reza Ansari
Keyword(s):  
Crystal Structure ◽  
Photonic Crystal ◽  
Optical Communication ◽  
Communication Systems ◽  
Fdtd Method ◽  
Ring Resonators ◽  
Photonic Crystal Structure ◽  
Square Lattice ◽  
Resonant Cavities ◽  
All Optical

Abstract Digital encoders are one of the key devices required in optical communication and digital signal processing systems. In this paper, a new photonic crystal structure is used to design all optical 4x2 encoder constructed from GaAs rods with square lattice in the pentane bachground based on plasmonic effect. Gold rods have also been used at the interface of dielectric rods and lines defect, which create plasmonic properties into the photonic crystal structure. The designed optical device is composed of four input waveguides and two output waveguides with two ring resonators at the resonant wavelength of 1.4mm with TM polarization. The presented encoder platform has the small size of 19 mm ×33 mm, that makes it to integration into all optical communication systems. The encoder operation is simulated and analyzed with numerical Finite Difference Time Domain (FDTD) method hand Plane Wave Expansion (PWE) method. In the proposed structure, we have shown that by selecting the appropriate radius size for the resonant cavities, the desirable wavelength can be obtained. The maximum values of transmission efficiency for the first and second outputs are 82% and 96%, respectively. Resonant cavities are also located in the crystal lattice in such a way that by activating third input, 50% and 48% of the input signal will be obtained in each output ports indicating (1,1) logic state. So the new plasmonic photonic crystal encoder could be future applicable in the field of optical computing.

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