All-optical logic operations based on silicon-on-insulator waveguides

Abstract

.Silicon waveguides are particularly appealing for the implementation of all-optical (AO) signal processing devices and switches due to the improved fabrication technology of silicon. Therefore, a silicon-on-silica waveguide is employed as the building block for simulating fundamental AO logic operations, including XOR, AND, OR, NOT, NOR, NAND, and XNOR, at 1.33-μm telecommunications wavelength. The proposed waveguide consists of two microring resonators and three strip waveguides. The operation concept of these logic gates relies on the constructive and destructive interference that results from the phase difference induced by incident optical beams. The performance of the target logic gates is assessed against the contrast ratio (CR) metric. The simulation results suggest that, by exploiting the proposed waveguides, these gates can operate with higher CR and faster speed compared to other designs.

High-Performance All-Optical Logic Operations Using Ψ-Shaped Silicon Waveguides at 1.55 μm

“…In this context, the mesh accuracy of the xyz axis is adjusted to 0.05 µm, 0.05 µm, and 0.01 µm, respectively. The obtained results indicate that when these logic functions are designed using the proposed waveguide, they can operate at 120 Gb/s and with higher CRs than other reported designs [11,[16][17][18]21,25,26,[30][31][32][33][34]. Consequently, AOLGs and signal processing could be accomplished with comparatively better performance to efficiently meet the current and future demands of modern photonic circuits and networks.…”

“…, where I out is the intensity at the output port (i.e., port 4) and I in = I 1 + I 2 + I 3 is the sum of the intensities at the three input ports [24][25][26][27][28]. Port 4 generates a logical output of '1' only when T > T th and a logical output of '0' otherwise.…”

“…The default simulation parameters are given in Table 1 [25,26]. To ensure that these parameters used in [25,26] achieve a high CR, we have run the FDTD simulations iteratively until we are sure of their suitability. The normalized spectral transmission (T) and the loss as a function of the operating wavelength (λ) are displayed in Figure 2 for the case where all the incident beams are launched at the three input ports with an identical phase of 0 • .…”

“…On the other hand, all-optical logic gates (AOLGs) overcome the inherent limitations of their electronic equivalents, particularly the small bandwidth and low speed of data transport, thereby allowing for better information processing [9,10]. Recently, AOLGs have been realized using a variety of waveguide designs , such as photonic crystal (PC) waveguides [11,20], silicon waveguides [21][22][23][24][25][26][27][28], gold nanowire waveguides [29], gold disk-shaped nanoparticles [30], metal slot waveguide networks [31], one-dimensional metal-insulator-metal structures [32], dielectric-metal-dielectric designs [33], dielectric-loaded waveguides [34], graphene compact microdisk resonators [35], and semiconductor optical amplifiers [36], which have been employed to realize AOLGs. Each of these reported designs has its own unique design and different features, which has led to publication.…”

All-Optical XOR, AND, OR, NOT, NOR, NAND, and XNOR Logic Operations Based on M-Shaped Silicon Waveguides at 1.55 μm

“…On the other hand, optical logic operations can have potential advantages in terms of speed and energy efficiency as compared to traditional electronic circuits [ 9 , 10 ]. Indeed, optical logic gates have recently been designed and/or constructed utilizing a variety of waveguide designs [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Implementing complete optical computing systems based on optical logic functions is a challenging task because it involves maintaining signal integrity over long distances, dealing with issues such as signal loss and dispersion, and developing practical devices that can be integrated into larger systems.…”