Design of three-bit binary to gray converter based on metal-insulator-metal plasmonic waveguides.

Using the finite element method and COMSOL version 5.5, a three-bit binary to gray converter with three plasmonic substructures and five input and three output ports was designed. Using a 520n m×200n m metal-insulator-metal plasmonic structure, the plasmonic converter was developed. In this configuration, the transmission threshold (T t h r e s h o l d ) is set to 45% at an operating wavelength of 1310 nm. Utilizing the modulation depth, contrast ratio (CR), and insertion loss criteria, the effectiveness of the plasmonic converter is evaluated. For the first, second, and third output terminals, the CR has respective values of 40.1 dB, 9.3 dB, and 9.2 dB.

Realization of an optical nanostructure 4×1 multiplexer based on metal-insulator-metal plasmonic waveguides.

The optical multiplexer was created at a nanoscale plasmonic structure utilizing the finite element method (FEM) with COMSOL version 5.5 software to enable maximum light confinement, high-speed optical systems, and a tiny structure. The metal-insulator-metal technology at a nanoscale dimension is used for creating the 4×1 multiplexer. In this design, the transmission threshold (T t h r e s h o l d ) is selected to be 100% for separating between logic "1" and logic "0" at a 1310 nm operating wavelength. The modulation depth (MD), contrast ratio (CR), and insertion loss (IL) characteristics were explained to evaluate the performance of the multiplexer. The CR has 3.48 dB, the MD offers an ideal performance with 95.28 %, and the IL has 3.31 dB.

Unequal channel spacing 8×5 Gbps optical system utilizing different signal representations.

Data representations are important to communication networks; they convert the data bits into a signal form, which affects the system capacity, maximum bit rate, transmission distance, and different linear and nonlinear impairments. In this paper, we propose non-return-to-zero (NRZ), chirped NRZ, duobinary, and duobinary return-to-zero (DRZ) data representations with eight dense wavelength division multiplexing channels for transmitting a 5 Gbps data rate through a 250 km fiber length. The results of the simulation design are calculated at different equal and unequal channel spacings, and the quality factor is measured over a wide range of optical power. For equal channel spacing, the DRZ has a preferable performance with a 28.40 quality factor at 18 dBm threshold power, and the chirped NRZ has a preferable performance with a 26.06 quality factor at 12 dBm threshold power. For unequal channel spacing, the DRZ has a 25.76 quality factor at 17 dBm threshold power, and the NRZ has a 25.06 quality factor at 10 dBm threshold power.

5 × 5 Gbps DWDM optical system with DCF and cascaded repeaters techniques.

Dispersion and attenuation problems are the most important factors that limit dense wavelength division multiplexing (DWDM) system performance. Dispersion causes pulse broadening of the optical spectrum, and the attenuation degrades the optical signal. In this paper, dispersion compensation fiber (DCF) and cascaded repeaters techniques have been proposed to reduce linear and nonlinear problems by using two different modulation formats (carrier-suppressed return zero [CSRZ] and optical modulator) and two various channel spacings (100 and 50 GHz). The cascaded repeater offers the best performance at 100 GHz channel spacing with 37 quality factors for CSRZ and optical modulation schemes; however, the DCF network design is more compatible with the CSRZ modulation format with 27 quality factors. For 50 GHz channel spacing, the cascaded repeater offers the best performance with 31 quality factors for CSRZ and optical modulator techniques; the DCF technique comes in next with 27 quality factors for CSRZ and 19 for optical modulators.

Multiple-input hybrid plasmonic OR logic gate with a nanostructure.

A multiple-input hybrid plasmonic OR logic gate has been constructed, analyzed, and simulated utilizing the finite element method by using the COMSOL software package version 5.5. To realize the suggested three- and four-input hybrid plasmonic OR gate, constructive and destructive interference has been standard among the input ports and control port. The factors used to evaluate the functionality of the nanoscale gate are the contrast ratio, modulation depth (MD), and insertion losses (ILs). In contrast, the optical power ratio at the output port, known as the transmission value (T value), has been measured and used to distinguish between logic 1 (ON-state) and logic 0 (OFF-state). The transmission threshold value in this article was 25%, and the wavelength range considered to display the result was from 1000 to 2000 nm. The three-input hybrid OR gate occupied a size of 500n m×400n m with transmission amplification results from the best T value of 216.5 % with 98.85% as a MD. In comparison, the four-input OR gate comes with a size of 600n m×400n m at the best T value of 301.5%, supported by a 99.33% as the MD. The IL values for the three-input and four-input designs are -4.07 and -5.4d B, respectively. The system resonance wavelength is 1310 nm.

Structure of 4 × 2 optical encoder based on hybrid plasmonic waveguides.

The optical 4×2 encoder is organized with a structure of dimensions 920n m×400n m, a resonance wavelength of 1310 nm, and a transmission threshold value of 30%. Based on the finite element method with the COMSOL software package, the proposed hybrid plasmonic encoder has been suggested, analyzed, and simulated, standing on the fundamentals of the constructive and destructive interferences between the light waves. The results were delivered in graphs containing the transmission values versus a wavelength range from 800 to 2000 nm, magnetic field distribution, contrast ratio, modulation depth, and insertion losses. The maximum transmission value reached was 68.4%; the modulation depth was 92.34%; and the contrast ratio was 11.1 dB.

All-optical design for multiplexer and comparator utilizing hybrid plasmonic waveguides.

Two optical combinational logic circuits, namely a 2×1 multiplexer and a comparator utilized by hybrid plasmonic waveguides, have been designed, analyzed, and simulated standing on the finite element method (FEM) with a COMSOL software package version 5.5. Transmission at the output port versus a wavelength range from 800 to 2000 nm, the contrast ratio, the modulation depth, and the insertion loss are the aspects used to estimate the circuits' functionality. The realization of these circuits was based on the fundamentals of the constructive and destructive interferences among the input and the biasing ports. The multiplexer circuits require a single substructure with a measurement of 400×400nm and delivers the best transmission of 202.3% and 99.75% as a modulation depth, while the comparator performed by three substructures with a 1300×400nm overall size offers a 202.6% as the best transmission and 99.99% modulation depth in the Equality situation. The operating wavelength and the magnitude of the transmission threshold are 1310 nm and 0.3, respectively.