Super Strong Wide TM Mie Bandgaps Tolerating Disorders

This study demonstrates the appearance of super intense and wide Mie bandgaps in metamaterials composed of germanium rods in air that tolerate some disordering of rod position and rod radius under transverse magnetic (TM) polarized light waves. Results for Mie bandgap modes TM01 and TM11 tolerate rod-position disordering of 50%, and rod-radius disordering of 34 and 20%, respectively. Using these characteristics of TM11 under position and radius disordering, ultra-narrow straight, L-shaped and crossing waveguides that contain 14, four, and two rows of Ge rods in air are designed. Also, it is shown that TE01 Mie bandgap appear in metamaterials contain high refractive index, and disappear in metamaterials with lower refractive index such as silicon; in contrast, a new phenomenon of intense and broadband TM01, TM11, and TM21 in metamaterials with lower refractive index such as silicon appear. Also, in Si-based metamaterials, TM01 tolerates high rod-position and rod-radius disordering of 50% and 34%, respectively, and TM11 shows robustness to rod-position and rod-radius of 20%. This strong tolerance of disordering of TM modes in silicon and germanium metamaterials opens a new way to design small, high-efficient, and easy-fabricable optical devices for optical integrated circuits.

Research on Fano Resonance Sensing Characteristics Based on Racetrack Resonant Cavity

To reduce the loss of the metal–insulator–metal waveguide structure in the near-infrared region, a plasmonic nanosensor structure based on a racetrack resonant cavity is proposed herein. Through finite element simulation, the transmission spectra of the sensor under different size parameters were analyzed, and its influence on the sensing characteristics of the system was examined. The analysis results show that the structure can excite the double Fano resonance, which has a distinctive dependence on the size parameters of the sensor. The position and line shape of the resonance peak can be adjusted by changing the key parameters. In addition, the sensor has a higher sensitivity, which can reach 1503.7 nm/RIU when being used in refractive index sensing; the figure of merit is 26.8, and it can reach 0.75 nm/°C when it is used in temperature sensing. This structure can be used in optical integrated circuits, especially high-sensitivity nanosensors.

Proposal of a Cascade Photonic Crystal XOR Logic Gate for Optical Integrated Circuits with Investigation of Fabrication Error and Optical Power Changes

A compact and simple structure is designed to create an all-optical XOR logic gate using a two-dimensional, photonic crystal lattice. The structure was implemented using three waveguides connected by two nano-resonators. The plane wave expansion method was used to obtain the photonic band gap and the finite-difference time-domain method was used to investigate the behavior of the electromagnetic field in the photonic crystal structure. Examining the high contrast ratio and high-speed cascade, all-optical XOR on a chip, the effects of fabrication error and the changes in the input optical power showed that the structure could be used in optical integrated circuits. The contrast ratio and data transfer rate of the cascade XOR logic gate were respectively obtained as 44.29 dB and 1.5 Tb/s. In addition, the designed structure had very small dimensions at 158.65 μm2 and required very low power to operate, which made it suitable for low-power circuits. This structure could also be used as a NOT logic gate. Therefore, an XNOR logic gate can be designed using XOR and NOT logic gates.

Three-dimensional plasmonic nano-router via optical antennas

A three-dimensional (3D) nanoscale optical router is a much-desired component in 3D stacked optical integrated circuits. However, existing 3D routers based on dielectric configurations suffer from large footprints and nanoscale routers based on plasmonic antennas only work in a 2D in-plane scene. Here, we propose and experimentally demonstrate cross-layered all-optical 3D routers with nanoscale footprints. Optical slot antenna pairs are used to realize the routing of plasmonic signals between different layers for arbitrary direction in a broadband wavelength range. The routers are also integrated with waveguide directly for exploring further applications. Based on these router elements, a 3D network of optical butterfly interconnection is demonstrated for multi-directional all-optical data communication. The proposed configuration paves the way for optical cross-layer routing on the nanoscale and advances the research and applications for 3D plasmonic circuits with high integration density in the future.

Design and Simulation of a Very Fast and Compact All-Optical Full-Subtractor Based an Nonlinear Effect in 2D Photonic Crystals

In this paper, by using the non-linear effects and also destructive and constructive interferences between waveguides, we have designed and simulated an all-optical full-Subtractor based on two-dimensional photonic crystals. The proposed Subtractor has a very simple structure which is composed of 33×31 silicon rods immersed in air in a square lattice and involves three input ports (bits) and an additional waveguide to exhaust the unwanted light. We imposed some defect rods to control the behavior of the light. The used non-linear material, is a doped glass with 1.4×10− 14 m2/w non-linear refractive index which is very greater than the non-linearity refractive index of silicon, 3.46×10− 20 m2/w. Since the proposed structure is very simple and compact, it can be applicable in optical integrated circuits and optical calculations.

Wavelength Plasmonic Demultiplexer Based on Square-disk Resonators in MIM Waveguide

A palsmonic demultiplexer based on cascading square nanodisk resonators in a metal-insulator-metal (MIM) plasmonic waveguide is proposed in this paper. The basic structure of the proposed demultiplexer is a plasmonic filter which consists of two waveguides, a middle cavity and two square nanodisk resonators. According to the simulation results the transmission spectra Full Width at Half-Maximum (FWHM) in the proposed structure reaches about 10 nm.With appropriate choice of refractive index (RI) and geometrical parameters the proposed structure can be adjusted and modified. The prposed structure has low FWHM, high sensitivity and acceptable figure of marit (FoM). By putting three filters with the same dimensions together, a triple-channel demultiplexer with three different wavelengths in each of the channels is designed. The effect of cross talk in the designed demultiplexer is less than -25 dB. The proposed structure can be used in the large-scale photonic integration, ultra-compact demultiplexer devices, nanosensors, integrated plasmonic devices and the development of optical integrated circuits. These structures numerically studied using Finite- Different Time- Domain (FDTD) simulations.

Investigation on two dimensional photonic crystal based two/three input all optical AND gate

In this paper the design and analysis of two dimensional photonic crystals based all optical AND logic gate is investigated. A logic gate implements a Boolean function and thus performs a logical operation on one or several logic inputs in order to produce a single logic input. The proposed all optical AND gate is designed with line and point defect using a hexagonal lattice with “Y” shaped defect. In order to meet the requirements for high speed networks the proposed gate designed. The functional parameters such as contrast ratio, bit rate, normalized efficiency and response time are calculated. The performance of the AND gate is analyzed by using the Finite Difference Time Domain method. The proposed logic gate is designed to operate at 1550 nm. It provides high contrast ratio and minimum delay time. Hence it is suitable for optical sensors and optical integrated circuits.

High contrast ratio for full-designs optical logic gates based on photonic crystal ring resonator

The all-optical logic gates have become an important key enabling in optical integrated circuits and find applications in optical networks. In this paper, we introduce new complete series of optical logic gates using photonic crystals. These designs formed by compilation with interference based defect and resonance phenomenon. The proposed work based on two dimensional square lattices by putting gallium arsenide (GaAs) rods immersed on air background. The maximum contrast ratio and the maximum working bit rates is obtained for the NOT/XOR and OR logic gates equal to 50.81 dB and 12.5 Tb/s, respectively. The simulation and optimization of structure is approved out using Finite-Difference-Time-Domain (FDTD) method and Plane Wave’s Method (PWEM).

Design and Analysis of a Dispersion-engineered and Highly Nonlinear Rib Waveguide for Generation of Broadband Supercontinuum Spectra

In this paper, a waveguide consisting of a core of As2Se3 chalcogenide glass and the upper and lower claddings of MgF2 with two zero-dispersion wavelengths (ZDW) has been proposed. By optimization of the dimensions of the core and the claddings, their effects on the dispersion curve have been investigated and a suitable structure with a flat dispersion curve, an effective mode area of ​​1.6 μm2 in a pump wavelength of 2.8 μm, and hence, a nonlinear coefficient greater than 34 w−1 m−1 has been obtained. A broadband supercontinuum in a wavelength range of 1.5 μm to 15 μm has been generated by applying an input pulse with duration of 100 fs and a maximum power of 2 kw to this waveguide. Due to the large width of the supercontinuum generated (SCG), the short length of the waveguide (maximum 5 mm), and a low input power, this structure is suitable for use in optical integrated circuits and its various applications.