Performance analysis of all optical 2 × 1 multiplexer in 2D photonic crystal structure

In optical processing systems, multiplexer is used to design optical devices such as arithmetic logic unit (ALU) and shift register (SR). Through this paper, we investigate the application of nonlinear photonic crystal ring resonator (PhCRR) based on nonlinear Kerr effect for realizing an all optical 2 × 1 multiplexer. The structure consists of two PhCRRs and five optical waveguides using hexagonal lattice silicon (Si) rods with a background of air. Performance of all optical 2 × 1 multiplexer is replicated with the help of finite difference time domain (FDTD) procedure at a wavelength of 1571 nm, and simulations presented an ultra-compact optical structure with ultra-fast switching speed.

Bottom-Up Synthesis of Mesoporous TiO2 Films for the Development of Optical Sensing Layers

Many optical sensors exploit the interesting properties of porous materials, as they ensure a stronger interaction between the light and the analyte directly within the optical structure. Most porous optical sensors are mainly based on porous silicon and anodized aluminum oxide, showing high sensitivities. However, the top-down strategies usually employed to produce those materials might offer a limited control over the properties of the porous layer, which could affect the homogeneity, reducing the sensor reproducibility. In this work, we present the bottom-up synthesis of mesoporous TiO2 Fabry-Pérot optical sensors displaying high sensitivity, high homogeneity, and low production cost, making this platform a very promising candidate for the development of high-performance optical sensors.

Tunable Nanosensor With a Horizontal Number Eight-Shape Cavity in a MIM Waveguide System

Optical devices play an important role in different fields, such as refractive index detection in food processing and the biochemical industry. In our work, a novel nanoscale optical structure, composed of a metal-insulator-metal waveguide with a stub and a horizontal number eight-shape cavity (HNEC), is presented. The transmission properties of this structure are investigated in detail by using finite element method The effects of geometric parameters on sensing performance are studied in detail. Moreover, the influences of an asymmetric resonator caused by shifting central rectangular cavity of HNEC on transmission spectrum are discussed. The changing parameters of HNEC resonator have different effects on different resonance dips. Then, when the parameters of this presented structure are fixed as a of 540 nm, b of 340 nm, S of 0, l of 70 nm and g of 10 nm, this intriguing structure can serve as a refractive index sensor, whose maximum sensitivity can reach 1,500 nm/refractive index unit with a figure of merit of 75. Therefore, this structure will contribute to the development of miniaturization of optical devices.

SODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY, PROPERTIES

SODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY PROPERTIES. The α-PbO nanocrystals were successfully decorated using sodium laureth sulfate (SLS) anionic surfactant. The method used is one-pot synthesis approach. The precursor used is lead nitrate (Pb(NO3)2). The UV-Vis spectrophotometer showed the absorption peak of α-PbO nanocrystals was seen at wavelength of 237 nm and an absorbance value of 0.7. The optical properties of PbO nanocrystals can be seen at the bandgap value of 4.2 eV. FT-IR spectroscopy showed the shift of absorption peak at the wavenumber of 1358 cm-1. XRD spectroscopy showed the crystals of PbO at diffraction angles (2θ) of 10-80o: 29.17, 32.54, 37.85, 39.62, 45.16, 46.21, 56.12, and 61.73 with miller indices of (111), (200), (201), (121), (220), (030), (311), and (032), respectively. The crystal size average of PbO was 56.32 nm. The results of PSA and PZC shows the particle size distribution of PbO is 71.5 nm with inter-particle charge of -25 mV. SEM-EDX data shows the PbO nanocrystals have an irregularly spherical with a compounds composition of Pb (83.12%) and O (16.88%). From the data of characterization, it can be concluded the PbO nanocrystals was successfully decorated using the surfactant anionic of sodium laureth sulfate.

Graphene-based tunable broadband polarizer for infrared frequency

This paper proposes the tunable graphene-assisted polarizer structure which is working on the infrared frequency range. The tunable polarizer has been designed by a three-layered structure of silica, graphene, and gold. The polarizer behavior of the structure is analyzed for the frequency range of 3 to 12 THz. The tunability of the structure is analyzed for the different values of fermi energy which is tunable parameter of single-layer graphene sheet. Polarizer response is derived in terms of different performance parameters such as reflectance, phase variation, phase difference, polarization conversion rate, and effective refractive indices. Graphene-based polarizer structure is investigated for the co-polarization and cross-polarization input incident conditions to check linear to circular polarization conversion. It also shows an effective refractive index response to check the metasurface behavior of the polarizer for 3 to 12 THz range. We have observed that the polarization amplitude becomes stronger for the higher Fermi energy value of the graphene sheet. The reflection amplitude is achieved up to 90%. Results of the proposed polarizer structure can be used to design the various electro-optical structure which operates in the lower THz range.