scholarly journals All-Optical Ultra-Fast Graphene-Photonic Crystal Switch

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 461 ◽  
Author(s):  
Mohammad Reza Jalali Azizpour ◽  
Mohammad Soroosh ◽  
Narges Dalvand ◽  
Yousef Seifi-Kavian

In this paper, an all-optical photonic crystal-based switch containing a graphene resonant ring has been presented. The structure has been composed of 15 × 15 silicon rods for a fundamental lattice. Then, a resonant ring including 9 thick silicon rods and 24 graphene-SiO2 rods was placed between two waveguides. The thick rods with a radius of 0.41a in the form of a 3 × 3 lattice were placed at the center of the ring. Graphene-SiO2 rods with a radius of 0.2a were assumed around the thick rods. These rods were made of the graphene monolayers which were separated by SiO2 disks. The size of the structure was about 70 µm2 that was more compact than other works. Furthermore, the rise and fall times were obtained by 0.3 ps and 0.4 ps, respectively, which were less than other reports. Besides, the amount of the contrast ratio (the difference between the margin values for logics 1 and 0) for the proposed structure was calculated by about 82%. The correct switching operation, compactness, and ultra-fast response, as well as the high contrast ratio, make the presented switch for optical integrated circuits.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Priyanka Pathak ◽  
Rukhsar Zafar ◽  
Vinay Kanungo ◽  
Sandeep Vyas

AbstractPhotonic crystal waveguides provide a way to manipulate the performance of an optical signal in an ultra-small volume and are quite viable in designing chip-based components that will work all-optically. Here, in this article an all-optical half adder is proposed. It is based on a square lattice photonic crystal waveguide in which silicon rods are arranged periodically. The photonic crystal offers a wide photonic band-gap in the desired region of telecommunication wavelength (i. e. near λ = 1550 nm. The performance of half Adder is measured using the contrast ratio and response time. The contrast ratio for sum and carry is 5.2 dB and 16.7 dB, respectively. The proposed half adder is miniaturized in size and having a footprint of 49 µm2 only. The total response time of the proposed adder is 1.4 picoseconds only. So, the device offers a high bit rate of 0.714 Tb/sec. The proposed half adder is an optimum choice for its application in on-chip optical integrated circuits.


Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 392
Author(s):  
Ahmad Mohebzadeh-Bahabady ◽  
Saeed Olyaee

A compact and simple structure is designed to create an all-optical XOR logic gate using a two-dimensional, photonic crystal lattice. The structure was implemented using three waveguides connected by two nano-resonators. The plane wave expansion method was used to obtain the photonic band gap and the finite-difference time-domain method was used to investigate the behavior of the electromagnetic field in the photonic crystal structure. Examining the high contrast ratio and high-speed cascade, all-optical XOR on a chip, the effects of fabrication error and the changes in the input optical power showed that the structure could be used in optical integrated circuits. The contrast ratio and data transfer rate of the cascade XOR logic gate were respectively obtained as 44.29 dB and 1.5 Tb/s. In addition, the designed structure had very small dimensions at 158.65 μm2 and required very low power to operate, which made it suitable for low-power circuits. This structure could also be used as a NOT logic gate. Therefore, an XNOR logic gate can be designed using XOR and NOT logic gates.


2006 ◽  
Vol 05 (06) ◽  
pp. 743-746
Author(s):  
SHOUZHEN HAN ◽  
JIE TIAN ◽  
CHENG REN ◽  
XINGSHENG XU ◽  
ZHIYUAN LE ◽  
...  

The abstract should summarize the context, content and conclusions of the paper in less than 200 words. We fabricated a two-dimensional Y-branch photonic crystal waveguide in the near infrared region by using focused ion beam etching and depositing system. The light guide characters of the waveguide were measured for three different spaces between branches. Field intensity distributions of TE polarized wave in the branches were simulated by using the transfer matrix method. Both the theoretical and experimental results show that the shortest space between branches of the photonic crystal waveguide is about 1.4 times wavelength of transmitted light. If the space became shorter, the light in the two branches would couple to each other seriously. This result might be helpful for the design of compact wave demultiplexer and all-optical integrated circuits.


Frequenz ◽  
2020 ◽  
Vol 74 (11-12) ◽  
pp. 417-426
Author(s):  
K. Rama Prabha ◽  
R. Arunkumar ◽  
S. Robinson

AbstractIn this paper the design and analysis of two dimensional photonic crystals based all optical AND logic gate is investigated. A logic gate implements a Boolean function and thus performs a logical operation on one or several logic inputs in order to produce a single logic input. The proposed all optical AND gate is designed with line and point defect using a hexagonal lattice with “Y” shaped defect. In order to meet the requirements for high speed networks the proposed gate designed. The functional parameters such as contrast ratio, bit rate, normalized efficiency and response time are calculated. The performance of the AND gate is analyzed by using the Finite Difference Time Domain method. The proposed logic gate is designed to operate at 1550 nm. It provides high contrast ratio and minimum delay time. Hence it is suitable for optical sensors and optical integrated circuits.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Asghar Askarian

AbstractIn this paper, ultra-fast, compact and high contrast ratio all optical half subtractor based on photonic crystal designed and simulated. The proposed design will be constructed using both threshold switching and interference of beams mechanisms. The proposed structure is composed of six waveguides and a nonlinear ring resonator. The simulation results show that the contrast ratio for D and B ports were obtained about 18.80 and 15.05 dB, respectively. Also the maximum rise, fall and steady-state times and total footprint for suggested all optical half subtractor are 0.5, 0.25, 1.5 ps and 234 μm2, respectively.


2021 ◽  
Author(s):  
Reza Beiranvand ◽  
Ali Mir ◽  
Reza Talebzadeh

Abstract In this paper, by using the non-linear effects and also destructive and constructive interferences between waveguides, we have designed and simulated an all-optical full-Subtractor based on two-dimensional photonic crystals. The proposed Subtractor has a very simple structure which is composed of 33×31 silicon rods immersed in air in a square lattice and involves three input ports (bits) and an additional waveguide to exhaust the unwanted light. We imposed some defect rods to control the behavior of the light. The used non-linear material, is a doped glass with 1.4×10− 14 m2/w non-linear refractive index which is very greater than the non-linearity refractive index of silicon, 3.46×10− 20 m2/w. Since the proposed structure is very simple and compact, it can be applicable in optical integrated circuits and optical calculations.


2022 ◽  
Vol 54 (2) ◽  
Author(s):  
R. Arunkumar ◽  
V. Kavitha ◽  
K. Rama Prabha ◽  
K. Latha ◽  
S. Robinson

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.


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