scholarly journals Improving the Performance of 2-To-4 Optical Decoders Based on Photonic Crystal Structures

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 635 ◽  
Author(s):  
Mohammad Javad Maleki ◽  
Mohammad Soroosh ◽  
Ali Mir
Keyword(s):  
Photonic Crystal ◽  
Square Lattice ◽  
Band Diagram ◽  
Plane Wave Expansion ◽  
Optical Signals ◽  
Spatial Periodicity ◽  
Electric And Magnetic Fields ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time ◽  
Optical Decoder

In this study, a novel, two-dimensional photonic crystal-based structure for the 2-to-4 optical decoder is presented. The structure consists of 23 rows and 14 columns of chalcogenide rods that are arranged in a square lattice with a spatial periodicity of 530 nm. The bias and the optical signals are guided toward the main waveguide through the three waveguides. Two unequal powers are applied to the input ports to approach the different intensities proportional to four working states into the main waveguide. Four cavities including the nonlinear rods are in response to drop the optical waves toward the output ports. To calculate the band diagram and the spatial distribution of the electric and magnetic fields, the plane wave expansion and the finite difference time domain methods have been used. The delay time of the designed structure is obtained around 220 fs, which is less than one for the previous structures. Furthermore, the gap between the margins for logic 0 and 1 is equal to 83%, which is higher than one for other works. Besides, the area of the structure is reduced to 90 µm2 in comparison to all reported structures. Based on the mentioned results, it seems that an improvement of the performance for 2-to-4 optical decoders has been obtained in this research.

An Optical Power Divider Based on Two-dimensional Photonic Crystal Structure

2017 ◽  
Vol 38 (2) ◽  
Author(s):  
Nazanin Mesri ◽  
Hamed Alipour-Banaei
Keyword(s):  
Photonic Crystal ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Optical Power ◽  
Power Divider ◽  
Two Dimensional ◽  
Plane Wave Expansion ◽  
Dimensional Photonic Crystal ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

AbstractIn this paper, an optical power divider with one input and four outputs has been proposed in a two-dimensional photonic crystal with triangular lattice and simulated using dielectric holes in an air substrate. The dividing properties of the power divider have been numerically simulated and analyzed using the plane wave expansion and finite difference time domain methods. The results show that the transmittance of this divider can be as high as 94.22 % for

Design of a new two-dimensional optical biosensor using photonic crystal waveguides and a nanocavity

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Hamideh Mohsenirad ◽  
Saeed Olyaee ◽  
Mahmood Seifouri
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Point Defects ◽  
Finite Difference Time Domain ◽  
Optical Biosensor ◽  
Two Dimensional ◽  
Plane Wave Expansion ◽  
Photonic Crystal Waveguides ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

AbstractIn this paper, a two-dimensional photonic crystal biosensor for medical applications based on two waveguides and a nanocavity is presented. The waveguides and nanocavity are created by introducing line and point defects into a photonic crystal, respectively. It could be shown that by injecting an analyte into a sensing hole, and thus changing its refractive index, may shift the resonant wavelength. The proposed structure is designed for the wavelength range of 1.5259–1.6934 μm. Sensitivity, the most important biosensor parameter, was studied and found to be approximately equal to 83.75 nm/refractive index units (RIU). An important specification of this structure is its very small dimensions. Two-dimensional finite-difference time domain and plane-wave expansion methods were used for both to simulate the proposed structure and to obtain the band diagrams.

scholarly journals A novel proposal based on 2D linear resonant cavity photonic crystals for all-optical NOT, XOR and XNOR logic gates

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kouddad Elhachemi ◽  
Naoum Rafah
Keyword(s):  
Finite Difference Time Domain ◽  
Resonant Cavity ◽  
Logic Gates ◽  
Low Power Consumption ◽  
Plane Wave Expansion ◽  
Novel Structure ◽  
All Optical ◽  
Easy Integration ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

AbstractIn this paper, we are going to propose a novel structure of all-optical NOT, XOR and XNOR logic gates are presented using a two-dimensional photonic crystal (2D-PhC). This structure is optimized by varying the radius of the cavity, to obtain a quality factor Q = 1192, and also has several ports of entry and one port of output. The size of each structure is equal to 85.8 μm2. The contrast ratios for the structures proposed all-optical NOT, XOR and XNOR logic gates between levels “0” and “1” are, respectively, 25.08, 25.03, and 14.47 dB. The response time for the three logical gates is 8.33 ps, and the bit rate is calculated at about 0.12 Tbit/s, all simulations are based on both numerical methods such as finite difference time domain (FDTD) and plane wave expansion (PWE). Designed logic gates are characterized by low power consumption, compactness and easy integration.

SECOND HARMONIC GENERATION IN TWO-DIMENSIONAL PHOTONIC CRYSTAL CONSISTING OF CENTRO-SYMMETRIC DIELECTRIC

2005 ◽  
Vol 19 (05) ◽  
pp. 869-878 ◽  
Author(s):  
JIANPING SHI ◽  
XIANZHONG CHEN ◽  
XUNAN CHEN ◽  
HANMIN YAO ◽  
GAIRONG YANG ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Photonic Crystal ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Finite Difference Time Domain ◽  
Second Harmonic ◽  
Electric Quadrupole ◽  
Waveguide Length ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

We report optical second harmonic generation (OSHG) in a two dimension photonic crystal of centro-symmetric dielectric based on finite difference time domain (FDTD) algorithm. The electromagnetic field distribution in the structure and the intensity of second harmonic (SH) from electric quadrupole polarization along the waveguide are analyzed. The results show that the acute spatial variation of electromagnetic field results in the radiation of SH, and the intensity is proportional to the square of waveguide length. When the beam intensity of the pumping wave is 1.3 MW/mm2, which has wavelength of 10.6 μm, the conversion efficiency of power is 0.307% for a photonic crystal of Silicon with a length of 40 μm.

scholarly journals Design and Analysis of a Slot Photonic Crystal Waveguide for Highly Sensitive Evanescent Field Absorption Sensing in Fluids

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 781
Author(s):  
Reyhaneh Jannesari ◽  
Gerald Pühringer ◽  
Thomas Grille ◽  
Bernhard Jakoby
Keyword(s):  
Photonic Crystal ◽  
Evanescent Field ◽  
Slab Thickness ◽  
Photonic Crystal Waveguide ◽  
Dielectric Slab ◽  
Plane Wave Expansion ◽  
Highly Sensitive ◽  
Center Position ◽  
Sensitive Sensor ◽  
Difference Time

The design and modeling of a highly sensitive sensor based on a slot photonic crystal waveguide (slot-PCWG) is presented. The structure consists of cylindrical air rods drilled in a dielectric slab on a triangular lattice, which are filled with SiO2. The waveguide is formed by removing elements from the regular photonic crystal grid in a row, and embedding a slot in the center position. This concept allows for a vast enhancement of the evanescent field ratio, leading to a strong overlap between the field of the waveguide mode and the analyte. In the present work, we show that the sensitivity at the constant slab thickness of the slot-PCWG modes is greatly enhanced, up to a factor of 7.6 compared with the corresponding PCWG modes or Si-slab WGs. The finite-difference time-domain (FDTD) technique and plane wave expansion (PWE) methods were used to study the dispersion and profile of the PCWG mode. The simulation results show the potential of this design, which will be fabricated and tested in the following steps of the project.

Design and Analysis of Self-Collimation-Based Photonic Crystal Beam Splitter

2014 ◽  
Vol 887-888 ◽  
pp. 417-421
Author(s):  
Hong Jing Li ◽  
Li An Chen
Keyword(s):  
Photonic Crystal ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Beam Splitter ◽  
Practical Applications ◽  
Beam Splitters ◽  
Output Surface ◽  
Fdtd Simulations ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

We present a self-collimation-based beam splitter in a two-dimensional photonic crystal (2D-PC) by introducing defects near the termination. From the equi-frequency contour (EFC) calculations and the finite-difference time-domain (FDTD) simulations, we show that the defects can give rise to the splitting of self-collimated beams in 2D-PCs and the directivity of the deflected beam can be improved by the defect along the PC surface. In order to get different kinds of beam splitters, including the Y-shaped, one-to-three, one-to-four structures, and so on, we only need to modify the structure of the output surface (along X-M direction). The proposed splitter may have practical applications in integrated photonic circuits.

Design and Fabrication of Novel Photonic Crystal Waveguide Consisting of Si-Ion Implanted SiO2 Layers

2010 ◽  
Vol 459 ◽  
pp. 168-172 ◽  
Author(s):  
Amarachukwu Valentine Umenyi ◽  
Masashi Honmi ◽  
Shinya Kawashiri ◽  
Teruyoshi Shinagawa ◽  
Kenta Miura ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Fdtd Method ◽  
Design Parameters ◽  
Photonic Crystal Waveguide ◽  
Atomic Force ◽  
Telecommunication Wavelength ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time ◽  
Si Ion Implantation ◽  
Ion Implanted

In this paper, we designed and fabricated two-dimensional photonic crystal (2-D PhC) consisting of the silicon ion (Si-ion) implanted silicon dioxide (SiO2) layers. The PhC design parameters based on the telecommunication wavelength (λ=1.55 µm) were obtained using finite-difference time-domain (FDTD) method. By analyzing the samples fabricated using different fabrication approach; we found a suitable fabrication method for 2-D PhCs based on the Si-ion implanted SiO2 layers. We have analyzed the fabricated sample using atomic force microscope (AFM) and annealing temperature and time were optimized in order to recover the damage done by Si-ion implantation. The implantation of Si-ion into SiO2 with the process of 2-D PhCs structure can effectively guide light inside such structure, which can easily be integrated into the existing silicon technology for directing light from one part of the chip to the other.

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