All-optical half adder based on cross structures in two-dimensional photonic crystals

Abstract

We propose an all-optical half adder based on two different cross structures in two-dimensional photonic crystals. One cross structure contains nonlinear materials and functions as an "AND" logic gate. The other one only contains linear materials and acts as an "XOR" logic gate. The system is demonstrated numerically by the FDTD method to work as expected. The optimal operating speed without considering the response time of the nonlinear material, the least ON to OFF logic-level contrast ratio, and the minimum power for this half adder obtained were 0.91 Tbps, 16 dB and 436 mW, respectively. The proposed structure has the potential to be used for constructing all-optical integrated digital computing circuits.

Bandwidth Improvement for a Photonic Crystal Optical Y-splitter

“…It is shown that in order to reduce the computational process, the slab structure can be modeled by a 2D structure of infinite height with an effective index [10][11], [14], [20][21][22][23][24][25]. In [21] a detailed study regarding the replacement of 3D analysis with 2D analysis has been made.…”

Ultracompact all-optical logic gates based on nonlinear plasmonic nanocavities

“…However, the large size of the bulk ferromagnetic and lithium niobate crystals, of the order of several millimeters, is unsuitable for practical chip-integrated applications [10,11]. Various schemes have been proposed to demonstrate all-optical basic logic gates based on linear interference mechanisms (or thirdorder nonlinear optical effects) in photonic microstructures and plasmonic nanostructures, such as photonic crystals [12][13][14][15][16][17][18][19][20][21][22][23], microring resonators [24][25][26][27][28][29][30], nanobridges [31], graphene-oxide films [32,33], photonic and plasmonic nanowires [34][35][36], metamaterials [37][38][39], and semiconductor optical amplifiers [40,41]. The extremely high requirements placed on the light paths for the linear interference mechanism and relatively small third-order nonlinear susceptibility of conventional materials result in a low output logic state contrast of <10 dB and high signal intensities of several GW/cm 2 for basic all-optical logic gates.…”

Realization of All Optical Full Adder by Utilizing DM Soliton Pulses

“…The most widely used all-optical schemes for implementation of adder are All optical integrated full adder-subtractor and demultiplexer using SOA-based Mach-Zehnder interferometer [2], photonic crystals [3], dark/ bright solitons [4],quantum dot SOA based MZI [5] In this paper a simple novel all-optical full adder is simulated at 100Gb/s by employing the XGM(Cross Gain Modulation) in semiconductor optical amplifier This circuit uses dispersion managed soliton pulses as input signal and it can be used opamp circuits, adaptive filter implementation, processors, arithmetic circuits etc.…”