Optical Logic Devices based on Photonic Crystal

2012

Journal of Physics: Conference Series, 2012

We have designed AND, NOT, and NOR logic gates based on photonic crystal structure employing cross-waveguide geometry with nonlinear rods using finite difference time domain (FDTD) method. The logical function is based on the frequency resonance shift of the microcavity caused by Kerr nonlinearity. The proposed devices benefit a simple and small structure, and clear operating principle.

2018

All-optical NOT logic gate is a basic element in all-optical signal processing and optical telecommunication systems. This logic gate is used to increase processing speed and data transmission [1]. All-optical logic gates based on fiber have difficulty in chip scale integration, and optical logic gates based on waveguide interferometers have a complicated structural arrangement. Moreover, the performance of logic gates with a micro resonator structure and semiconductor optical amplifiers are limited to moment emission noise [2]. Photonic crystals (PC) are a new class of dielectric materials proposed by Yablonovitch and John which can be used in making photonic integration devices with dimensions equal to a wavelength [3]. Presence of photonic crystals (PC) in the design of all-optical logic gates leads to a high potential in compression and reduction of the size of ultra-fast switching devices as well as reduction in power consumption [4].Photonic crystals transmit or reflect light ...

Progress In Electromagnetics Research C

The aim of this paper was to propose and design a photonic crystal drop filter based on ring resonators and study its properties numerically. This structure is constituted in a two-dimensional square lattice. The resonant wavelengths of the PCRR proposed are λ = 1.553 µm, and the extraction efficiency exceeds 99% with a quality factor of 5177. To study the all-optical OR and XOR logic gate function, we calculated the electric field distribution of the 2D photonic crystal for the 1.553 µm signal light. In order to have a large selectivity of filtering and also of having a fast switching in the field of nonlinearity, we increase the number of ring resonators, and the latter are used for designing all optical logic gates which work using the Kerr effect equal to 10 −6 m 2 /w.

International Journal of Electronics and Telecommunications, 2021

The research carried out in the field of optics and photonics with an idea to design and develop the all optical logic devices in the fascinating material known as photonic crystals (PhCs). The structural investigation reveals that the two dimensional (2-D) PhCs is more suitable for fabrication of optoelectronic components. In this article we have designed basic logic gates in 2-D PhCs as they are the building blocks for the construction of optical devices and in these, refractive index is periodically modulated with the wavelength. The understanding of light behaviour in complex PhCs helps in creating photonic band gap (PBG) that can prevent light of certain wavelength propagating in crystal lattice structure. For the selected geometry structure, three PBG bands will exists out of which two of them are transverse electric (TE) and one is transverse magnetic (TM) mode. The PBG bands in the TE mode ranges from 0.31(a λ) to 0.46(a λ), 0.61(a λ) to 0.63(a λ) and TM mode ranges from 0.86(a λ) to 0.93(a λ). The free space wavelength of 1550 nm is set for the finite difference time domain (FDTD) simulation of the structure. The response time and computational overhead required for the proposed OR gate is 0.128ps and 4.4MB is obtained. Also we calculated the extinction ratio for AND gate and NOT gate as 6.19 dB and 10.21 dB respectively.

Optical and Quantum Electronics, 2022

In this review, a comprehensive summary on photonic crystal based all-optical logic decoder reported in the last decade has been made. The articles reviewed are primarily grouped into two broad tributaries based on linear and nonlinear regimes of optical interactions inside photonic crystal structures. The reasons behind choosing PhC structures are because of their excellent abilities to control and guide the flow of optical signal along with the intense light-matter interaction in sub-wavelength scale, which have been utilized substantially to realize decoder circuits. Each group of the articles has been analysed extensively, and their prospective merits and demerits are discussed in terms of different performance metrics such as operating speed, requirement of power, footprint, contrast ratio between output logic levels etc. The review concludes while focusing on prospective discussions on the issues for further advancements in this field based on different techniques.

Photonic Sensors, 2012

Optical logic gates are elementary components for optical network and optical computing. In this paper, we propose a structure for AND, NAND, XNOR and NOR logic gates in the two dimensional photonic crystal which utilizes the dispersion based self-collimation effect. The self-collimated beam is splitted by the line defect and interfered with other self-collimated beam. This interference may be constructive or destructive based on their phase difference. This phenomenon is employed to realize all-optical logic gates. The gates are demonstrated numerically by computing electromagnetic field distribution using the finite difference time domain (FDTD) method. The results ensure that this design can function as AND, NAND, XNOR and NOR logic gates. The size of the structure is about 10 μm×10 μm which in turn results in an increase in the speed and all the gates are realized in the same configuration. The ON-OFF contrast ratio is about 6 dB.

Optics Express, 2011

This article demonstrates theoretical design of ultracompact alloptical AND, NAND, OR, and NOR gates with two-dimensional nonlinear photonic crystal slabs. Compound Ag-polymer film with a low refractive index and large third-order nonlinearity is adopted as our nonlinear material and photonic crystal cavities with a relatively high quality factor of about 2000 is designed on this polymer slab. Numerical simulations show that alloptical logic gates with low pump-power in the order of tens of MW/cm 2 can be achieved. These design results may provide very useful schemes and approaches for the realization of all-optical logic gates with low-cost, lowpump-power, high-contrast and ultrafast response-time.

2016

Optical logic gates are key elements of optical network. This paper reviews different types of All Optical logic gates, various methods and materials used for construction of logic gates using photonic crystal (PhCs), discusses their novel properties, and reports recent advances in PhC components. We present a study of various structures used for construction of optical gates and methods used for construction like finite difference time domain and beam propagation method adapted by various researchers. By analyzing these comparisons we conclude that using 2-D PhC and finite difference time domain method we can improve the performance and reduce the size of optical logic gates.

Optical and Quantum Electronics, 2014

All-optical logic gate with multifunctional performance have been designed theoretically in a two-dimensional photonic crystal waveguide (PCW) structure using multimode interference principle. A two dimensional finite-difference time domain (2D-FDTD) was employed in our numerical simulations. It is shown that by switching the optical signal to different input waveguide ports, the proposed device can function as XOR, OR, NOR and NOT gates simultaneously or individually. It is also shown that by a combination of photonic band gap and total internal reflection effects in PCWs, the device can operate for both, transverse electric (TE) and transverse magnetic (TM) polarizations. Our simulation results show that the optimized devices have very good transmission efficiencies, a broad frequency range and the contrast ratio are extending to high than 21 dB for TE and 17 dB for TM polarization. The total width and length of the devise are 2.16 and 8.20 µm respectively achieving miniaturization. It is a kind of promising device for next generation logic optical circuits, ultrahigh speed signal processing, and future photonic crystal based all-optical integrated circuits. Keywords Photonic band gap (PBG) • Total internal reflection (TIR) • Finite difference time domain (FDTD) • All-optical logic gates • Multimode interference (MMI)