Photonic Crystal Ring Resonator Research Articles

All optical NAND/NOR and majority gates using nonlinear photonic crystal ring resonator

Abstract All optical logic gates are building blocks for all optical data processors. One way of designing optical logic gates is using threshold switching which can be realized by combining an optical resonator with nonlinear Kerr effect. In this paper we showed that a novel structure consisting of nonlinear photonic crystal ring resonator which can be used for realizing optical NAND/NOR and majority gates. The delay time of the proposed NAND/NOR and majority gates are 2.5 ps and 1.5 ps respectively. Finite difference time domain and plane wave expansion methods were used for simulating the proposed optical logic gates. The total footprint of the proposed structure is about 988 μm2.

Design and analysis of photonic crystal ring resonator based 6 × 6 wavelength router for photonic integrated circuits

A photonic crystal ring resonator-based 6 × 6 router has been designed and reported. The router is designed using silicon pillars with a refractive index of 3.47 perforated in the air background of refractive index 1 in a square lattice with a lattice constant of a = 562 nm. The router is designed to operate in the third optical window wavelength which has low loss and most widely used in optical communication systems and networks. Plane-wave expansion and finite difference time domain method has been used to obtain the bandgap and performance of the designed router, which exhibits acceptable performance such as low insertion loss, low propagation delay, and low crosstalk. These routers will find applications in the photonic integrated circuit that paves a path to all-optical networks.

An all optical photonic crystal half adder suitable for optical processing applications

Abstract Increasing the speed of operation in all optical signal processing is very important. For reaching this goal one needs high speed optical devices. Optical half adders are one of the important building blocks required in optical processing. In this paper an optical half adder was proposed by combining nonlinear photonic crystal ring resonators with optical waveguides. Finite difference time domain method wase used for simulating the final structure. The simulation results confirmed that the rise time for the proposed structure is about 1 ps.

Comparison of two loop photonic crystal: ring-resonator with hexagonal and rectangular lattice structure

Recent years have witnessed significant exploration in photonic crystal (PC)-supported optical devices owing their competence in incorporation of optoelectronic components and miniaturization. Various structures of these devices have been explored in the literature with the aim to improve the performance. This paper compares two loop ring-resonators (horizontal and vertical arrangements) with hexagonal and rectangular lattice structures. Paper reports the outperformance of two loop PC ring-resonator for wavelengths of 0.85 μm, 1.3 μm and 1.55 μm, respectively, for hexagonal lattice-based two loop ring-resonator having vertical arrangement at width of 30 with Q-factor that are 22,500, 26,000 and 38,700 due to effective confinement of light and out-of-plane loss and propagation loss.

Numerical Analysis of Reconfigurable and Multifunctional Barium Titanate Platform Based on Photonic Crystal Ring Resonator

A novel reconfigurable, reversible and multifunctional nanostructure platform is designed with ultracompact size, high extinction ratio, large bandwidth and low optical loss. The proposed structure consists of a ring resonator and photonic crystal waveguides. The single nanoscale structure is used to realize the five different high-performance photonic devices such as, electro-optic tunable filter, reconfigurable switch, 1 × 5 power splitter, 4 × 2 reversible encoder and SR flip-flop. These miniature optical device performance parameters are numerically analyzed and optimized by finite-difference-time-domain (FDTD) method. A multifunctional ring resonator coupled waveguide structure is designed with a very small footprint of 179 μm2, large bandwidth of 45.2 nm, the fast response time of 215 fs and high data rate of 4.651 Tbps. Hence, the proposed nanostructure can be highly suitable for photonic interconnects, lightwave communication networks and quantum computing.

Analysis of a photonic crystal temperature sensor based on Z-shaped ring resonator

A 2D photonic crystal (PC) sensor based on optical filter has been designed using a PC ring resonator (PCRR). The sensor used a 2D-PCRR triangular lattice with circular silicon rods placed in air background. We employed a ring resonator with Z-shaped core in the investigated structure, which is designed as temperature sensor and investigated theoretically along with high quality factor, transmission and sensitivity parameters. For sensing analysis, the 2D finite-difference time-domain method and the plane-wave expansion approach have been applied. A temperature variation from 0 to 20 °C causes a defect mode shifting and the channel filter wavelength shift was used as sensing mechanism. Using the number of the functionalized rods N = 36 at the temperature of 5 °C, the quality factor, the temperature sensitivity, the refractive index sensitivity and the detection limit of the studied structure were found to be 57,104, 96 pm/°C, 400 nm/RIU and 6.16 × 10–6 RIU, respectively.

Photonic crystal based narrowband optical filter: A brief analysis

In this paper, for a narrow band filter function, a two-dimensional photonic crystal with a hexagonal-shaped resonator has been proposed. The filter design consists of a 2D hexagonal lattice with silica rods (dielectric) placed in the air (substrate) with a lattice constant of 0.65 μm and rod radius of 0.25 μm produced on a wafer of size 10 μm * 13 μm. The filter is made up of a bus waveguide, dropping waveguide and a photonic crystal ring resonator (PCRR) by introducing defects in the crystalline edifice. The optimization is carried in the structure over the entire C band using the finite difference time domain (FDTD) method. And the performance of the designed structure can be calculated with the parameters like transmission efficiency and Q-factor. For the proposed edifice the transmission efficiency and Q-factor are 87 % and 389 at resonance wavelength 1556 nm, 80 % and 782 at resonance wavelength 1564 nm. The optimized filter provides a narrowband transmission suitable for DWDM applications to design multiplexers and de-multiplexers that obtains higher capacities in optical fiber for current as well as future demands.

Compact 4-bit all optical digital to analog converter based on photonic crystal ring resonators

A compact all optical 4-bit digital-to-analog converter (DAC) based on 2D photonic crystals is proposed to operate in the III transmission window 1550 nm of optical communication systems. The DAC consists of a photonic crystal ring resonator whose operation is based on the nonlinear Kerr effect. The overall operation of the proposed DAC is analyzed using the finite difference time domain method and plane wave expansion method. The total footprint of the proposed structure is 1150 µm2 with silicon rods of refractive index equal to 3.4641 placed in an air substrate with a 2D square lattice, exhibiting an insertion loss of −11 dB and absolute error of 2.79% which is suitable for photonic integrated circuits.

Demonstration of mid-infrared slow light one-dimensional photonic crystal ring resonator with high-order photonic bandgap.

Integrated mid-infrared sensing offers opportunities for the compact, selective, label-free and non-invasive detection of the absorption fingerprints of many chemical compounds, which is of great scientific and technological importance. To achieve high sensitivity, the key is to boost the interaction between light and analytes. So far, approaches like leveraging the slow light effect, increasing optical path length and enhancing the electric field confinement (f) in the analyte are envisaged. Here, we experimentally investigate a slow light one-dimensional photonic crystal ring resonator operating at high-order photonic bandgap (PBG) in mid-infrared range, which features both strong field confinement in analyte and slow light effect. And the optical path length can also be improved by the resoantor compared with waveguide structure. The characteristics of the first- and second-order bandgap edges are studied by changing the number of patterned periodical holes while keeping other parameters unchanged to confine the bands in the measurement range of our setup between 3.64 and 4.0 µm. Temperature sensitivity of different modes is also experimentally studied, which helps to understand the field confinement. Compared to the fundamental PBG edge modes, the second PBG edge modes show a higher field confinement in the analyte and a comparable group index, leading to larger light-matter interaction. Our work could be used for the design of ultra-sensitive integrated mid-infrared sensors, which have widespread applications including environment monitoring, biosensing and chemical analysis.

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

AbstractThe 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).

All-optical analog to digital converter based on nonlinear photonic crystal ring resonators

Optical analog to digital conversion is very important for implementing all-optical data processing systems. In this study, we designed an all-optical analog to digital converter using photonic crystal nonlinear ring resonators. The main goal of this study was to design an optical analog to digital converter with no upper limit for the input optical intensity when generating “11” codes at the output ports. Simulation results showed that the maximum rise time for the proposed structure is about 1.5 ps

Phase-change photonic crystal ring resonator for reconfigurable directional-coupler switching

A novel compact photonic crystal ring resonator is designed based on phase-change material (PCM) to realize reconfigurable directional-coupler switching for the two wavelengths of coarse wavelength division multiplexing (CWDM) system at 1530 nm and 1550 nm. The working mechanism of this PCM-based device is analyzed from the perspective of the coupled optical field in the inner and outer resonator rings during the phase transition of selected photonic crystal rods. This kind of PCM-based directional-coupler switches will play a strong role in the reconfigurable lattice mesh-based integrated intelligent photonic system.

Creation of a fast optical Toffoli gate based on photonic crystal nonlinear ring resonators

All-optical reversible logic gates can play crucial roles in the next generation of all-optical computing systems. In this paper, we will propose and design an all-optical Toffoli gate using photonic crystal-based nonlinear ring resonators. The proposed structure has three input and three output ports. There is a one-by-one mapping between the input and output ports; therefore, the proposed structure is a reversible gate with the maximum time delay about 2 ps and suitable for optical communication applications.

Design of a High-Quality Optical Filter Based on 2D Photonic Crystal Ring Resonator for WDM Systems

AbstractIn this article, a 2D photonic crystal (PC)-based optical filter has been designed using a PC ring resonator. The resonator used is of square type with a square lattice constant, which has been designed by increasing the radius of the inner rods of the resonator. The filter designed can separate the light of the wavelength of 1545.3 nm with a transmission coefficient of 98 %. The bandwidth of the above wavelength is equal to 0.5 nm and hence the quality factor of the device at this wavelength is equal to 3091. The effects of the structural parameters, such as the refractive index, the lattice constant, the radius of the dielectric rods, the radius of the inner rods of the resonator on the behavior of the proposed device, are fully investigated. To obtain the photonic band gap, the plane wave expansion method is used. In addition, the finite difference time domain method is used to examine, simulate, and to obtain the output spectrum of the structure. The designed structure has both high transmission coefficient and quality factor. Comparatively speaking, it is also simple to design which justifies its use in other photonic crystal-based optical devices.

Topological photonic crystal fibers and ring resonators.

With an exact recursive approach, we study photonic crystal fibers and resonators with topological features induced by Aubry-Andre-Harper cladding modulation. We find nontrivial gaps and edge states at the interface between regions with different topological invariants. These structures show topological protection against symmetry-preserving local perturbations that do not close the gap and sustain strong field localization and energy concentration at a given radial distance. As topological light guiding and trapping devices, they may bring about many opportunities for both fundamentals and applications unachievable with conventional devices.

All-optical non-gate and NOR gate design of two-dimensional photonic crystal ring resonator

All-optical non-gate and NOR gate design of two-dimensional photonic crystal ring resonator

Photonic crystal ring resonator based optical MUX/DEMUX design structures: a survey and comparison study

For the past few decades, the design of photonic crystal (PC)-based optical devices and components are mainly focused by several researchers as miniaturisation becomes a crucial need in many integrated applications. In optical communication system, the PC-based wavelength division multiplexer and demultiplexer is considered as one of the most essential component as it offers high transmission rate in single optical fibre by performing multiplexing operation. Due to its major role, numerous optical MUX/DEMUX structures based on different design mechanisms like resonant cavity, super prism effect, cascading multiple channel drop filters, coupling and cascading the PC waveguide, defect waveguides and photonic crystal ring resonator (PCRR), etc., have been reported and analysed so far. However, despite the various mechanisms, the design structure based on PCRR mechanism has attracted the attention of many researchers in recent years due to its design flexibility, high quality factor and low loss which satisfies the requirements of major applications. Hence, the main aim of this paper is to discuss about the various existing design structures of optical MUX/DEMUX based on PCRR mechanism along with its respective pros and cons. Further, the comparison of their corresponding structural and performance parameters is also tabulated in detail. From the literature review and comparison study, the future design considerations are suggested for the researchers which would be helpful for them in designing better structure with improved performance.

An all-optical half subtractor based on Kerr effect and photonic crystals

Optical half subtractor is one of the optical logic gates, which is very important for realizing all optical computing systems. The aim of this paper is to design a new structure for realizing an all-optical half subtractor based on photonic crystal nonlinear ring resonators. For this purpose, three nonlinear ring resonators are combined with the some optical waveguides to create the desired structure. A finite difference time domain method will be utilized to analyze and simulate the proposed structure. The simulation results show that the contrast ratio for D and B ports are 6.81 dB and 7.78 dB respectively. Moreover, the maximum rise and fall times for the proposed structure are 1.5 ps and 1 ps respectively.

Compact eight-channel wavelength demultiplexer using modified photonic crystal ring resonators for CWDM applications

An eight-channel wavelength demultiplexer by cascading of ring resonators (RRs) in photonic crystal (PhC) structure is proposed in this paper. In designing of this demultiplexer, we used eight square-shaped PhC RRs with different refractive index (RI) of defect rods to generate a distinctive resonance wavelength. Each PhC RR has a specific resonance wavelength with tuning a variety of design parameters such as RI of a whole, defect and inner rods and radius of defect rods. In operating wavelength of λ0 = 1497 nm, the transmission power and quality factor (Q) of single RR are discovered as 96% and 1000, respectively. The average power transmission, channel spacing, crosstalk and full width at half maximum are found by finite difference time domain method to be about 96 ± 1%, 2.25 nm, − 35 dB and 1.5 nm, respectively. Simulation outcomes demonstrate that the designed demultiplexer has a proper operation. The footprint of the designed device is about ~ 115 μm2, which makes this device a promising for future photonic integrated circuits.

A novel proposal for an all-optical 2-bit adder/subtractor based on photonic crystal ring resonators

Optical addition and subtraction are very crucial functions required in all optical computations and processing. In this article we propose an all-optical circuit that can implement these functions simultaneously. The proposed device can be realized by combining optical XOR gates with a 2-bit full adder. Four nonlinear ring resonators are used to realize the proposed structure.