Nanophotonic interferometer realizing all-optical exclusive or gate on a silicon chip

Abstract

We present an all optical approach allowing the realization of microscale logic exclusive or ͑XOR͒ gate based on special interferometer configuration. The operation device includes two close optical waveguides realized on a silicon chip. A thin metallic layer of a few nanometers that separates the two waveguides causes a relative phase shift of between them. The structure performs interference of the two input beams while demonstrating XOR logic gate operation at the amplitude of the resulted output. The logic operation is realized after small propagation distance of Ͻ1.8 m.

Multilayer photonic logic gate integrated into microelectronic chip

“…(The choice of cobalt is just an initial choice according to Ref. 10; later the material chosen for the metal layer may be different.) It is evident from the results in Fig.…”

“…The introduction of metal between the waveguides contributes to additional accumulated phase which depends on the interaction length. 10,11 If we choose the length of the metal such that it causes a phase difference of π, when a signal is inserted into both waveguides, the phase difference causes a negative interference and the output is low. When light is inserted into only a single waveguide, the output is high, thus resulting in all-optical XOR operation.…”

“…These SiO 2 layers can be used to waveguide optical signals, and with the aid of the metallic lines, realize all optical logic operations, such as a XOR gate. 10 This approach enables us to combine electronic and optic data processing on the same chips, instead of reducing the size of the photonic devices; we can potentially utilize the entire space of the silicon chip for data processing. This approach enables better use of the volume of microelectronic chip in addition to electronic and optical computation side by side.…”

High‐Resolution 3D Printed Photonic Waveguide Devices

“…[3,4] There have been many designs put forward to realize the building blocks of optical logic units. Electron-beam (EB) lithography is frequently employed to fabricate devices with a resolution of a few nanometers; [5,6] Numerous successful applications in optical devices such as micro resonators with high-quality factors, nanophotonic waveguides with very low propagation loss, and other optical devices including interferometers and filters [7,8] have been demonstrated. This planar technology enables assembly of many individual elements on one chip, allowing for complex optical systems.…”

Photonic XOR with inherent loss compensation mechanism for memory cell implementation in a standard nanoscale very large-scale integrated fabrication process

“…The phase at the output of each of the XOR gates depends on the input waveguide. While the input into one waveguide results in an amplitude of logical "1" with zero phase, an input of "1" to the other waveguide will result in an output with the same amplitude but a phase of π [14]. This situation does not allow for cascading of the two XOR gates in order to construct the memory cell and can be rectified by phase encoding the input signals.…”