Plasmonic Microring Resonator Research Articles

Design and comprehensive analysis of an ultra-fast fractional-order temporal integrator using graphene-based hybrid plasmonic microring resonator

Design and comprehensive analysis of an ultra-fast fractional-order temporal integrator using graphene-based hybrid plasmonic microring resonator

High-sensitivity electrocardiogram sensor based on Fano resonance in a double-stub-assisted plasmonic micro-ring resonator

Detecting Electrocardiogram (ECG) signals remains a challenge due to its low signal amplitude and low frequency characteristic. In this paper, we suggest a solution to ECG sensor based on Fano resonance of surface plasma wave (SPW) in a Double-Stub-Assisted plasmonic micro-ring resonator (DS-PMRR) structure by exploiting the electro-optic (EO) effect of EO polymer. A theoretical model of Fano resonance of SPW in DS-PMRR is established to analyze the sensitivity of ECG sensor. A moderately symmetrical cone mode converter is designed to achieve the efficient coupling between silicon on insulator (SOI) waveguide and metal–insulator–metal (MIM) waveguide. The whole structure with an active zone as small as 5 μm × 8.4 μm × 0.2 μm is analyzed by finite-element method (FEM) and a sensitivity of 11740 pm/V is obtained. In combination with a sub-picometer optical spectrum analyzer, the proposed sensor can detect ECG signals with the magnitude on the order of 10 μv.

Ultra-compact and highly sensitive refractive index sensor based on a chalcogenide suspended slot hybrid plasmonic microring resonator

A microring resonator based on chalcogenide suspended slot hybrid plasmonic waveguide (CSSHPW) is designed for the refractive index (RI) sensing. The CSSHPW consists of a suspended Si nanowire with a nanoscale air gap and a Cu film deposited on a chalcogenide support layer. The mode characteristics of the suspended slot hybrid plasmonic mode (SSHPM) in the CSSHPW are simulated by using the finite element method (FEM). The simulation results show that the waveguide sensitivity (Swg) as high as 0.8 and the optical propagation loss as low as 0.08 dB/µm are obtained by optimizing the structure. The RI sensitivity (S), detection limit (DL), and detection range (DR) of the CSSHPW-based microring resonator (MRR) with a radius of 2 µm are 511.5 nm/RIU, 4.72 × 10−5 RIU, and 0.158 RIU, respectively. These superior performances as well as the fully complementary metal-oxide-semiconductor (CMOS) compatibility pave the way for CSSHPW-based biochemical sensors to realize on-chip high-S waveguide sensors. Moreover, the CSSHPW-MRR has a small size, high modulation depth, large Swg, and Cu cap of easy electrode formation, it facilitates the fabrication of a high-performance electro-optic (EO) modulator by infilling the slot with EO material.

A fair comparison of spectral properties of Slot and Hybrid plasmonic micro-ring resonators

In this work, we presented micro-ring resonator structures based on slot and hybrid plasmonic waveguides. The slot waveguide is formed by keeping a narrow air gap between two silicon strip waveguides. Whereas, the hybrid waveguide is composed of Metal-Air-Silicon structure, where the E-field is considerably enhanced in the narrow air gap. The transmission spectrum and E-field distribution of these structures are simulated using the finite element method (FEM). Micro-ring resonator based on hybrid plasmonic waveguide shows the best sensitivity of 333.3 nm/RIU. Whereas, slot waveguide based micro-ring resonator showed the best performance in Q-factor and the figure of merits.

Mode and sensing properties of a silicon-based hybrid plasmonic microring resonator

A silicon-based hybrid plasmonic microring resonator consisting of a silicon-on-insulator ring which is separated from a silver nanoring by a low-permittivity dielectric is proposed for sensing applications. Benefitting from the hybrid modes and the circular-shaped cross section of nanoring, the hybrid microcavity can attract part of the cavity energy from the silicon ring microcavity, achieving high energy ratio and high refractive index sensitivity. The performance of the hybrid microcavity has been investigated by employing a finite element method and analyzed considering the different structure geometry, showing high quality factor of 1181, small mode volume of 0.154 µm3 and large refractive index sensitivity of 529.6 nm/RIU (refractive index unit). Thus, the presented silicon-based hybrid plasmonic microring resonator provides the potential applications in sensing at deep sub-wavelength scale.

Single Plasmon Generation in an InAs/GaAs Quantum Dot in a Transfer-Printed Plasmonic Microring Resonator

We report single plasmon generation with a self-assembled InAs/GaAs quantum dot embedded in a plasmonic microring resonator. The plasmonic cavity based on a GaAs microring is defined on an atomically smooth silver surface. We fabricated this structure with the help of transfer printing, which enables the pick-and-place assembly of the complicated, heterogeneous three-dimensional stack. We show that a high-order surface-plasmon-polariton transverse mode mediates efficient coupling between the InAs/GaAs quantum dots and the plasmonic cavity, paving the way for developing plasmonic quantum light sources based on the state-of-the-art solid-state quantum emitters. Experimentally, we observed Purcell-enhanced radiation from the quantum dot coupled to the plasmonic mode. We also observed a strong antibunching in the intensity correlation histogram measured for scattered photons from the plasmonic resonator, indicating single plasmon generation in the resonator. Our results are important for the development of quantum plasmonic circuits integrating high-performance single plasmon generators.

Au-SiO2-Si hybrid plasmonic waveguide micro-ring resonator sensor

A refractive index sensor based on straight silicon waveguide and a hybrid plasmonic micro-ring resonator of radius 1 µm is presented. The hybrid waveguide is made up of a Metal-Insulator-Silicon structure, where the electric field is significantly enhanced in the thin insulator layer. The micro-ring design is optimized where silicon micro-ring waveguide width and a total height of the structure is 400 nm and 220 nm, respectively. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). Despite the small size of hybrid micro-ring resonator and sensing medium, the sensitivity is relatively high as compared to conventional dielectric micro-ring resonator sensors. The resonance shift of Δλ = 27 nm is obtained for Δn = 0.15 and yields the best sensitivity of 180 nm/RIU in the near infrared range.

Integrated plasmonic biosensors based on microring resonators

We introduce a biosensor scheme comprising a plasmonic microring resonator coupled with a plasmonic bus waveguide. The detection principle is based on the violation of the surface plasmon polariton resonance condition for the microring (which is sensitive to refractive index changes). Analytical calculations and simulations in COMSOL Multiphysics are presented. As a result, we obtained main characteristics of the sensor, such as sensitivity (S = 1200 nm) and Q-factor (Q ≈ 100).

Highly sensitive refractive index sensor based on hybrid plasmonic waveguide microring resonator

A refractive index (RI) sensor based on straight silicon strip waveguide and a hybrid plasmonic microring resonator is presented. The hybrid waveguide is made up of a Metal-Air-Silicon structure, where the electric field is significantly enhanced in the narrow air gap. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). Due to a large overlap of the optical field in the hybrid microring resonator and the sensing medium, this sensor can be used for both gas and bio sensing applications. The best sensitivity of 690 nm/RIU and 401 nm/RIU is obtained for gas and bio sensing, respectively. The obtained values are relatively high as compared to conventional dielectric microring resonator sensors. Our proposed sensor design has a potential to find further applications in biomedical science and nanophotonic circuits.

Demonstration of lasing oscillation in a plasmonic microring resonator containing quantum dots fabricated by transfer printing

We demonstrate room-temperature lasing oscillation in a plasmonic microring resonator containing InAs/GaAs self-assembled quantum dots. The resonator is composed of a GaAs microring placed on an atomically flat silver surface. Such a structure was fabricated by transfer printing, through which we can pick the dielectric microring and place it on the silver surface at will, hence maintaining a high-quality metal surface without introducing any complex fabrication process. Our result will be important in the development of nanoscale light sources in future densely integrated plasmonic circuits.

Highly Sensitive Biochemical Sensor Based on Two-Layer Dielectric Loaded Plasmonic Microring Resonator

In this paper, we propose and design a highly sensitive optical biochemical sensor based on two-layer dielectric loaded surface plasmon polariton waveguide (TDLSPPW)-based microring resonator (MRR). By optimizing the structure parameters, the propagation length of the proposed waveguide is ~126 μm, which is about 3 times of that of the polymer dielectric loaded surface plasmon polariton waveguide (DLSPPW) reported. It is demonstrated that the TDLSPPW-based MRR is operated at the under-coupling state, along with the quality factor (Q) of 541.2 and extinction ratio (ER) of 12.2 dB. Moreover, the Q and ER are much more sensitive to the structure parameters of the waveguide, including the waveguide width w, total thickness t, and coupling gap Wgap, compared to the low refractive index (RI) layer thickness t2. The simulation results on the biochemical RI sensing show that the sensitivities of 408.7 and 276.4 nm/RIU for glucose concentration in urine and chemical gases can be achieved, respectively. It is believed that the proposed sensor has potential applications in photonic-integrated biochemical sensing.

Silicon hybrid plasmonic microring resonator for sensing applications.

A novel silicon hybrid plasmonic microring resonator consisting of a silver nanoring on top of a silicon-on-insulator ring is proposed and investigated theoretically for possible applications in sensing at the deep subwavelength scale. By using the finite-element method, insight into how the mode properties (Q factor, effective mode volume, energy ratio, sensitivity) depend on the geometric structure of the hybrid microring resonator is presented. Simulation results reveal that this kind of hybrid microcavity maintains a high Q factor ∼600, an ultrasmall mode volume of 0.15 μm³, and high sensitivity of 497 nm/refractive index unit for refractive index sensing. The hybrid plasmonic microcavity with optimized geometric structures presented provides the potential for ultracompact sensing applications.

Classical Analog of Electromagnetically Induced Transparency in the Visible Range With Ultra-Compact Plasmonic Micro-Ring Resonators

We theoretically show that it should be possible to demonstrate Electromagnetic-Induced-Transparency-like (EIT-like) effects in the visible range by using ultra-compact plasmonic micro-ring resonators with μm 2 order foot print. By using the finite-difference time-domain (FDTD) numerical method and the coupled mode theory (CMT) collaboratively, the transmission intensity, phase, and group delay spectra of the coupled plasmonic ring resonators are theoretically calculated with the inclusion of metallic loss and dispersion through the Drude model. The interference induced transmission peak can be successfully achieved through suitable design of the plasmonic ring resonator structure.

All-optical logic operation of polarized light signals in highly nonlinear silicon hybrid plasmonic microring resonators.

All-optical logic operation is theoretically demonstrated by means of polarization-dependent four-wave mixing (FWM) processes in a highly nonlinear silicon hybrid plasmonic waveguide (HPWG) microring resonator. We design an ultra-compact (radii = 1 μm) microring resonator (MRR) that is realized by using a silicon HPWG with the capacity for subwavelength-bending. The HPWG exhibits very high confinement (Aeff~0.045 μm(2)) that can result in a remarkably high nonlinear parameter (γ~3000 W(-1) m(-1)), given a highly nonlinear gap material. By manipulating the polarization properties of the pump and signals with a very low electric field (|E|~10(8) Vm(-1)), all-optical NOT, NOR, and NAND logical operations are obtained through the FWM process. These compact all-optical nanoplasmonic devices are stable, fabrication simplified, and silicon on insulator (SOI) compatible.

A SIMPLE NANOSCALE PLASMONIC SQUARE-SHAPED RING RESONATOR WAVEGUIDE

A novel surface plasmon based square-shaped ring resonator with bending metal-dielectric- metal input/output (I/O) waveguide at optical spectral range is investigated. The influence of various geometric parameters is studied in detail, with parallel finite difference time domain method. The results validate that vertical coupling disturbance can be efficiently suppressed by employing the modified I/O structure. The transmittance performance has all the resonant frequencies workable with better extinction ratios, higher finesse and higher Q-factors compared to the original plasmonic micro-ring resonator. From these analyses, it is found that the proposed waveguide is outstanding in aspects of the total field extinction and frequency selectivity characteristic.

Enhanced mid-to-near-infrared second harmonic generation in silicon plasmonic microring resonators with low pump power

We propose an efficient and low-power second harmonic generation (SHG) process in a silicon-compatible hybrid plasmonic microring resonator. By making the microring resonator doubly resonant at the fundamental wavelength of 3.1 μm and second harmonic wavelength of 1.55 μm, the SHG efficiency is enhanced by almost two orders of magnitude when compared to the previous result induced in a straight plasmonic waveguide. A SHG efficiency of 13.71% is predicted for a low pump power of 20 mW in a ring with radius of 2.325 μm. This device provides a potential route for realizing efficient frequency conversion between mid-infrared and near-infrared wavebands on a chip.

Self-Pulsation in a Nonlinear Plasmonic Ring Resonator

We demonstrate the self-pulsing behavior in a nonlinear all-pass plasmonic microring resonator (MRR). The structure consists of a nonlinear metal-dielectric-metal (MDM) plasmonic waveguide and supports antisymmetric, backward propagating slow-modes. The slow modes are coupled to a feedback loop realized from a MDM waveguide, which supports symmetric, forward propagating fast modes. We calculate the temporal response of the system with a finite difference time domain method and show a SP behavior for input fields higher than a critical value. We perform a semi-quantitative description of the self-pulsation by solving iteratively, in time domain, the Ikeda equation of an all-pass MRR presenting a nonlinear phase shift. For this system, the pulses have a period of 300 fs with a modulation factor of 0.3. This configuration could be applied as a source of continuous wave terahertz radiation or as an optical clock in highly integrated plasmonic circuits.

Design and analysis of ultra-compact EO polymer modulators based on hybrid plasmonic microring resonators

Ultra-compact EO polymer modulators based on hybrid plasmonic microring resonators are proposed, simulated and analyzed. Comparing with Si slot microring modulator, hybrid plasmonic microring modulator shows about 6-times enhancement of the figure of merit when the bending radius is around 510 nm, due to its much larger intrinsic quality factor in sub-micron radius range. Influences of the EO polymer height and Si height on the device's performance are analyzed and optimal design is given. When operating with a bias of 3.6 V, the proposed device has optical modulation amplitude of 0.8 and insertion loss of about 1 dB. The estimated power consumption is about 5 fJ/bit at 100 GHz.

Polymer Hybrid Plasmonic Waveguides and Microring Resonators

We report the design and fabrication of hybrid plasmonic waveguides based on the Au/SiO2/SU-8 material system. Monolithic integration of these devices with dielectric SU-8 waveguides on the same chip enabled efficient and broadband coupling between photonic and plasmonic devices to be achieved. Compact hybrid plasmonic microring resonators were also demonstrated with high intrinsic Q-factors close to 300.

All-plasmonic switching based on thermal nonlinearity in a polymer plasmonic microring resonator

We experimentally investigated thermal nonlinear effects in a hybrid Au/SiO(2)/SU-8 plasmonic microring resonator for nonlinear switching. Large ohmic loss in the metal layer gave rise to a high rate of light-to-heat conversion in the plasmonic waveguide, causing an intensity-dependent thermo-optic shift in the microring resonance. We obtained 30 times larger resonance shift in the plasmonic microring than in a similar SU-8 dielectric microring. Using an in-plane pump-and-probe configuration, we also demonstrated all-plasmonic nonlinear switching in the plasmonic microring with an on-off switching contrast of 4 dB over 50 mW input power.