Photonic Crystal Ring Resonator Research Articles

Enhanced Fano resonances in a silicon nitride photonic crystal nanobeam-assisted micro ring resonator for dual telecom band operation

Silicon-based Micro Ring Resonators (MRR) are a powerful tool for the realization of label free optical biosensors. The sharp edge of a Fano resonance in a Silicon Nitride (Si3N4) platform can boost photonic sensing applications based on MRRs. In this work, we demonstrate enhanced Fano resonance features for a Si3N4 Micro Ring Resonator assisted by a Photonic Crystal Nanobeam (PhCN-MRR) operating in the TM-like mode at the O-band wavelengths. Our findings show that the fabricated PhCN-MRR results in increased asymmetric resonances for TM-like mode compared with TE-like mode operation in the C-band. As a result, a versatile and flexible design to realize Fano resonance with polarization dependent asymmetry in the C and O telecom bands is presented.

Quantum slow light annular photonic crystal ring resonator for optical network applications

Quantum slow light annular photonic crystal ring resonator for optical network applications

2D FDTD Electromagnetic Simulation of an Ultracompact All Optical Logic Gate Based on 2D Photonic Crystal for Ultrafast Applications

In this paper, the concept of photonic crystals (PhCs) is fundamental to designing and simulating an all-optical logic gate device. We proposed an all-optical switch composed of two-dimensional (2D) photonic crystal waveguides with a central photonic crystal ring resonator (PCRR). The new all-optical NAND logic gate device comprises two linear waveguides coupled to each other through a single compact PCRR. The plane wave expansion (PWE) and finite-difference time-domain (FDTD) methods are applied to simulate the properties of the system. The structure is implemented on the operational wavelength of 1700 nm on an air wafer of only 12 μm × 12 μm. Indeed, the simulation results show that the proposed all-optical NAND gate is a strong candidate for ultrafast photonic integrated circuits (PICs) for applications in optical communications, being advantageous with high transmitting power, with simple design, and without the use of optical amplifiers and nonlinear materials.

Spectral Engineering of Optical Microresonators in Anisotropic Lithium Niobate Crystal.

On-chip optical microresonators are essential building blocks in integrated optics. The ability to arbitrarily engineer their resonant frequencies is crucial for exploring novel physics in synthetic frequency dimensions and practical applications like nonlinear optical parametric processes and dispersion-engineered frequency comb generation. Photonic crystal ring (PhCR) resonators are a versatile tool for such arbitrary frequency engineering, by controllably creating mode splitting at selected resonances. To date, these PhCRs have mostly been demonstrated in isotropic photonic materials, while such engineering can be significantly more complicated in anisotropic platforms that often offer more fruitful optical properties. Here, the spectral engineering of chip-scale optical microresonators is realized in the anisotropic lithium niobate (LN) crystal by a gradient design that precisely compensates for variations in both refractive index and perturbation strength. Controllable frequency splitting is experimentally demonstrated at single and multiple selected resonances in LN PhCR resonators with different sizes, while maintaining high quality-factors up to 1 × 106. Moreover, a sharp boundary is experimentally constructed in the synthetic frequency dimension based on an actively modulated x-cut LN gradient-PhCR, opening up new paths toward the arbitrary control of electro-optic comb spectral shapes and exploration of novel physics in the frequency degree of freedom.

An all-optical 1*2 de-multiplexer based on two-dimensional nonlinear photonic crystal ring resonators

An all-optical 1*2 de-multiplexer based on two-dimensional nonlinear photonic crystal ring resonators

Design of an all-optical compact 2*1 multiplexer based on 2D photonic crystal ring resonators

Design of an all-optical compact 2*1 multiplexer based on 2D photonic crystal ring resonators

All-optical simultaneous OR and NAND gates using photonic crystal ring resonator and Kerr effect

All-optical simultaneous OR and NAND gates design is proposed using a simple nonlinear photonic crystal ring resonator based on the chalcogenide glass (Ag20As32Se48) material which is one of the promising materials for all-optical devices. The structure consists of an octagonal ring resonator between two waveguides, which uses the switching threshold mechanism based on the Kerr effect to perform two simultaneous logic gates functions. The plane wave expansion (PWE) method is used to obtain the band diagram in the proposed structure, and the two-dimensional finite difference time domain (2D-FDTD) method is used in the simulation to evaluate the performance of the proposed design. The resonance wavelength is 1551.3 nm, with a high transmission and coupling efficiency of about 100%. The proposed optical OR and NAND logic gates have high contrast ratios of 21.15 dB and 28.19 dB, respectively, with a quality factor of 596.65. The operating power intensity of the proposed structure is 1 kW μm−2, and the threshold power intensity is obtained at 2.8 kW μm−2. The proposed gates provide transmitted power of not less than 0.5. The size of the structure is 20.5 μm × 18.17 μm. The proposed structure is compact, works on low operational power intensity, and has the ability for dense integration. The simplicity and small size of the structure make it easy to fabricate for future integration in all-optical circuits.

Design and simulate the demultiplexer using photonic crystal ring resonator for DWDM system

In this study, a new four channel de-multiplexer with a ring resonator design is proposed. The bus waveguide and drop waveguide that make up the Ring Resonator are ring-shaped. In the proposed four channel demultiplexer design, one bus waveguide and four drop waveguides were built using a photonic crystal ring resonator. To improve output efficiency, the proposed demultiplexer was built with distinct inner radius values for each channel. With the resonance wavelengths for each channel in the range of 1552.4 nm, 1553.2 nm, 1554.1 nm, and 1555.4 nm, the suggested demultiplexer average quality factor was 7870.90, and its average transmission efficiency was 98.67%. The demultiplexer was created with a 0.8 nm narrow channel spacing with a − 15 dB to − 25 dB crosstalk range. The proposed ring resonator structure is made of silicon, which has a refractive index of 3.47, a center wavelength ranges of 1550 nm, and a lattice constant that varies with the radius range of 540 nm. To examine the performance, one can simulate the suggested demultiplexer structure using the FDTD (Finite-Difference Time-Domain) approach. The proposed work 198.7 µm2 footprint is appropriate for DWDM applications.

Silicon Photonic Crystal Ring Resonator With High-Quality-Factor

Silicon Photonic Crystal Ring Resonator With High-Quality-Factor

Design of high-Q photonic crystal ring resonator incorporating Gaussian distributed inner rods for refractive index sensor

Design of high-Q photonic crystal ring resonator incorporating Gaussian distributed inner rods for refractive index sensor

A new proposal of an all optical 2-bit adder based on 2D photonic crystal ring resonators

A new proposal of an all optical 2-bit adder based on 2D photonic crystal ring resonators

Photonic-crystal-based high-performance ring resonator using a topological interface state: design and analysis.

We propose a photonic crystal ring resonator for the enhancement of quality factor that supports two-dimensionally bounded topological edge states. Crystal parameters are obtained through finite-difference time-domain numerical simulation to get the enhanced quality factor using the topological properties of the photonic crystal. Topological edge states are created when two regions with dissimilar band topologies come together at an interface and are contained within a slab of dielectric material. These edge states can move along sharp edges without backscattering. The transmission dropout issue arises whenever the quality factor is enhanced in a conventional photonic system and is eliminated remarkably by employing the present approach. Such nanoscale photonic crystal structures promote robust interactions between quantum emitters and photonic edge states.

Efficient 1×2, 1×4, 1×8 and 1×16 photonic crystal filters/power splitters based ring resonators for modern passive optical network PON

In this paper, we propose a new architecture of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] optical filter/power splitters operating around 1.55[Formula: see text][Formula: see text]m, based on a CPs 2D photonic crystal ring resonator for Modern Passive Optical Network (PON). This type of functionality, filtering/power splitting is introduced in this work for the first-time according literature. The designed device consists of a square array of GaAs dielectric rods immersed in air. The structure is designed and successfully simulated by the finite element method using the software COMSOL Multiphysics. From the results obtained, we note that the beam is evenly distributed for all output ports with total efficient transmissions of about 99.6%, 98.8%, 97.1% and 96.8% and low insertion losses of about 0.017, 0.052, 0.128, and −0.14[Formula: see text]dB for the [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] filter power splitter successively.

An electro-optic comparator based on photonic crystal ring resonators covered by graphene nanoshells

A logic comparator is a digital circuit comprised of numerous transistors on an integrated circuit that compares two binary numbers. Researchers have proposed various designs for implementing comparators using logic gates, but most are based on DC electrical signals, which suffer from slow switching speeds and high power consumption. This paper presents a novel design for a fast and tunable electro-optic single-bit comparator utilizing graphene-coated nanoshells (GNSs) in photonic crystal (PhC) ring resonators. The comparator's structure includes three inputs, three GNS-coated ring resonators, several waveguides for comparison, and three outputs created in a PhC microstructure in an area of 760 µm². A continuous-wave laser source centered at 1550 nm is applied to the first input to enable the proposed photonic chip. Two other inputs are utilized to apply electrical voltages, and the comparator's task is to compare them. The optical signal applied to the enable input port is directed to the corresponding output depending on the comparison result. We used the finite-difference time-domain method to study the light propagation inside the proposed structure to solve Maxwell's equations. Numerical simulations demonstrate that the designed structure has a very short delay time of 1.85 ps, faster than previously reported comparators, including electronic, optoelectronic, and all-optical comparators. The proposed comparator's rapid response, small area, and tunability make it an appropriate device for optical applications in photonic integrated circuits.

High-speed all-optical digital-to-analog converter based on photonic crystal ring resonators

Abstract In this paper, a 2-bit all-optical digital-to-analog converter, including two ring resonators has been presented. Some nonlinear rods have been placed at the center of the rings which their refractive indices depend on the incoming optical intensity. Concerning the states of two input bits, each ring does the switching operation and guides the optical waves toward the output port. The finite difference time domain method has been used to calculate the electric and magnetic components of optical waves. The maximum absolute error of the digital-to-analog converter is equal to 2.43 %, less than the previous works. Also, the insertion loss varies from −11.13 dB to −8.57 dB for the different states. Besides, the maximum propagation time of the structure is just 1.8 ps suitable for high-speed applications.

A Solution for Detection of Ethanol and Methanol With Overlapping Refractive Indexes Based on Photonic Crystal Ring Resonator Optical Sensors

In this paper, a selective and sensitive photonic crystal (PC) sensor is designed to detect two types of alcohol, namely ethanol and methanol and to measure their concentration percentages. The use of different concentrations of each compound leads to a change in their densities which have definite correlations with the refractive indexes based on the Gladstone–Dale theory. According to the experimental results and the Gladstone–Dale theory, the value of the refractive index in different percentages of alcohols overlaps, which makes it difficult to detect them with optical techniques. We present a new solution to solve this problem, which is very interesting. The FWHMs for spectrum of the ethanol and methanol mixtures with water are obtained as 1.2 nm and 1.4 nm, respectively. This way, it is possible to distinguish between two types of alcohols. After this process and by diluting the solution of each of the alcohols below 30%, the overlap of the refractive indexes is prevented and the obtained resonance wavelength can be attributed to a determined percentage of alcohol. The performance parameters of the proposed sensor for both alcohols are quite promising so that the transmission, the quality factor, the sensitivity and the FOM are above 97%, 1092, 756 nm/RIU and 593.9 RIU-1 respectively. Even, when two typical samples have the same refractive indexes, the sensor can distinguish the alcohol type and the sample’s concentration. This capability along with the small size (123 μm2) and high sensitivity, are the special features of the proposed PC sensor.

Label-Free cancer cell biosensor based on photonic crystal ring resonator

A photonic crystal (PhC) biosensor is a compact device, which detects the changes of characteristic of the light due to binding the sample by the analyte. In this paper; we propose using ring resonator in two-dimensional (2D) photonic crystal biosensor. A periodic array of silicon rods with the refractive index of n = 3.46 in the air bacground formed a cubic lattice structure. The sensing mechanism occures when the the resonant wavelength shifts due to change in the the refractive index of analytes. The transmission spectrum shifts about 4.47 nm to the higher wavelengths by increasing the refractive index of analyte. This mechanism can recognize the normal, and cancerous cells. The average values of sensitivity, quality factor, FOM, and transmission for the designed structure are 308.5 (nm/RIU), 3803.55, 848.06 RIU-1 and 98.78 %, respectively. The reported structure has high quality promising applications for highly sensitive label-free optical biosensors.

Thermal tunable silicon valley photonic crystal ring resonators at the telecommunication wavelength.

Tunable ring resonators are essential devices in integrated circuits. Compared to conventional ring resonators, valley photonic crystal (VPC) ring resonators have a compact design and high quality factor (Q-factor), attracting broad attention. However, tunable VPC ring resonators haven't been demonstrated. Here we theoretically demonstrate the first tunable VPC ring resonator in the telecommunication wavelength region, the resonance peaks of which are tuned by controlling the temperature based on the thermal-optic effect of silicon. The design is ultracompact (12.05 µm by 10.44 µm), with a high Q-factor of 1281.00. By tuning the temperature from 100 K to 750 K, the phase modulation can reach 7.70 π, and the adjustment efficiency is 0.062 nm/K. Since thermal tuning has been broadly applied in silicon photonics, our design can be readily applied in integrated photonic circuits and will find broad applications. Furthermore, our work opens new possibilities and deepens the understanding of designing novel tunable VPC photonic devices.

Detection and Analysis of Bacterial Water using Photonic Crystal Ring-Resonator Based Refractive-Index Sensor on SOI Platform

A refractive-index biosensor is modeled using a photonic crystal ring resonator. The proposed sensor possesses a high selectivity and high quality-factor against different bacterial water samples. The introduction of the circular rim in the ring resonator structure is responsible for a sharp resonance that makes it suitable for detecting bacterial impurities. The sufficiently separated resonant peak for different samples offers a possibility of highly selective label-free bacterial water detection. The proposed biosensor is highly sensitive, real-time, lab-on-chip, and label-free, which is necessary for on-site detection. The proposed sensor is designed using a silicon-on-insulator platform.

High-order accurate numerical simulation of monochromatic waves in photonic crystal ring resonators with the help of a non-iterative domain decomposition

High-order accurate numerical simulation of monochromatic waves in photonic crystal ring resonators with the help of a non-iterative domain decomposition