scholarly journals Deep subwavelength Fabry-Perot resonances

2014 ◽  
Vol 1 ◽  
pp. 2 ◽  
Author(s):  
Cheng-Ping Huang ◽  
Che-Ting Chan
Keyword(s):  
Cavity Length ◽  
Ground Plane ◽  
Field Enhancement ◽  
Photonic Devices ◽  
Narrow Slit ◽  
Penetration Effect ◽  
Mechanical Oscillations ◽  
Fabry Perot ◽  
Potential Applications ◽  
Electromagnetic Pressure

Confinement of light by subwavelength objects facilitates the realization of compact photonic devices and the enhancement of light-matter interactions. The Fabry-Perot (FP) cavity provides an efficient tool for confining light. However, the conventional FP cavity length is usually comparable to or larger than the light wavelength, making them inconvenient for many applications. By manipulating the reflection phase at the cavity boundaries, the FP cavity length could be made much smaller than the wavelength. In this review, we consider the subwavelength FP resonance in a plasmonic system composed of a slit grating backed with a ground plane, covering the spectral range from microwave to THz and infrared regime. For very narrow slit width and spacer thickness, a typical zero-order and deep subwavelength FP resonance in the metallic slits can be strongly induced. Moreover, due to the subwavelength FP resonance, greatly enhanced electromagnetic pressure can also be induced in the system. The sign and magnitude of the electromagnetic pressure are dominated by the field penetration effect in the metal as well as the field enhancement in the FP cavities. The effect promises a variety of potential applications, such as detecting tiny motions and driving the mechanical oscillations.

scholarly journals Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 210
Author(s):  
Da Teng ◽  
Kai Wang
Keyword(s):  
Photonic Devices ◽  
Effective Index ◽  
The Finite Element Method ◽  
Index Method ◽  
Modal Properties ◽  
Terahertz Region ◽  
Effective Index Method ◽  
Integration Density ◽  
Device Integration ◽  
Potential Applications

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.

scholarly journals Achromatic terahertz Airy beam generation with dielectric metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Qingqing Cheng ◽  
Juncheng Wang ◽  
Ling Ma ◽  
Zhixiong Shen ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Frequency Dispersion ◽  
Light Sheet ◽  
Photonic Devices ◽  
Self Healing ◽  
Beam Focusing ◽  
Light Sheet Microscopy ◽  
Airy Beam ◽  
Potential Applications ◽  
Airy Beams

AbstractAiry beams exhibit intriguing properties such as nonspreading, self-bending, and self-healing and have attracted considerable recent interest because of their many potential applications in photonics, such as to beam focusing, light-sheet microscopy, and biomedical imaging. However, previous approaches to generate Airy beams using photonic structures have suffered from severe chromatic problems arising from strong frequency dispersion of the scatterers. Here, we design and fabricate a metasurface composed of silicon posts for the frequency range 0.4–0.8 THz in transmission mode, and we experimentally demonstrate achromatic Airy beams exhibiting autofocusing properties. We further show numerically that a generated achromatic Airy-beam-based metalens exhibits self-healing properties that are immune to scattering by particles and that it also possesses a larger depth of focus than a traditional metalens. Our results pave the way to the realization of flat photonic devices for applications to noninvasive biomedical imaging and light-sheet microscopy, and we provide a numerical demonstration of a device protocol.

Topological liquid crystal superstructures as structured light lasers

2021 ◽  
Vol 118 (49) ◽  
pp. e2110839118
Author(s):  
Miha Papič ◽  
Urban Mur ◽  
Kottoli Poyil Zuhail ◽  
Miha Ravnik ◽  
Igor Muševič ◽  
...  
Keyword(s):  
Self Assembly ◽  
Soft Matter ◽  
Structured Light ◽  
Topological Defects ◽  
Photonic Devices ◽  
Light Polarization ◽  
Self Healing ◽  
Fabry Perot ◽  
Self Assembled ◽  
External Stimuli

Liquid crystals (LCs) form an extremely rich range of self-assembled topological structures with artificially or naturally created topological defects. Some of the main applications of LCs are various optical and photonic devices, where compared to their solid-state counterparts, soft photonic systems are fundamentally different in terms of unique properties such as self-assembly, self-healing, large tunability, sensitivity to external stimuli, and biocompatibility. Here we show that complex tunable microlasers emitting structured light can be generated from self-assembled topological LC superstructures containing topological defects inserted into a thin Fabry–Pérot microcavity. The topology and geometry of the LC superstructure determine the structuring of the emitted light by providing complex three-dimensionally varying optical axis and order parameter singularities, also affecting the topology of the light polarization. The microlaser can be switched between modes by an electric field, and its wavelength can be tuned with temperature. The proposed soft matter microlaser approach opens directions in soft matter photonics research, where structured light with specifically tailored intensity and polarization fields could be designed and implemented.

Design and Simulation of an Electrically Pumped SPASER

2021 ◽  
Author(s):  
Ali Fattah ◽  
Abdolber Mallah Livani ◽  
Eliye Norouzi
Keyword(s):  
Surface Plasmons ◽  
Power Efficiency ◽  
Population Inversion ◽  
Cavity Length ◽  
Optical Gain ◽  
Photonic Devices ◽  
Forward Voltage ◽  
Pn Junction ◽  
Inversion Condition ◽  
Resonance Cavity

Abstract In this investigation, a novel SPASER is designed and simulated which uses a forward biased pn junction to induce population inversion condition. Simulations are performed by means of SILVACO software. In the proposed structure, the active region is considered as a direct bandgap material (InGaAs) and a larger bandgap material (InP) is used for p and n regions to form heterojunctions. This pn junction is in contact with gold and surface plasmons propagate along their interface. Free space wavelength of the oscillations of surface plasmons is 1550nm that is used in photonic devices, frequently. To form the resonance cavity of the SPASER, two high reflective mirrors are placed at the ends of the plasmonic waveguide. Applied forward voltage and absorption coefficient of the SPASER are 1.2V and − 0.33cm− 1, respectively. Thus, the optical gain for a 50 microns cavity length is 1cm− 1. Moreover, the power consumption of the proposed device at these conditions is 1.2mW. The output plasmonic power is 0.6mW which yields 50% power efficiency.

SIMULATION AND ANALYSIS OF ASYMMETRIC METAMATERIAL RESONATOR-ASSISTED MICROWAVE SENSOR

2010 ◽  
Vol 24 (12) ◽  
pp. 1207-1215 ◽  
Author(s):  
JINGJING YANG ◽  
MING HUANG ◽  
ZHE XIAO ◽  
JINHUI PENG
Keyword(s):  
Topological Structure ◽  
Asymmetry Parameter ◽  
Field Enhancement ◽  
Q Factor ◽  
Trapped Modes ◽  
Design Requirement ◽  
High Q ◽  
Dielectric Sample ◽  
Microwave Sensor ◽  
Potential Applications

Based on the field enhancement principle of trapped modes, two new asymmetric metamaterial resonators are presented. Transmission response (S21) of the rectangular wave-guide filled with an asymmetric metamaterial resonator is simulated. Results show that the asymmetric resonator possesses high Q-factor and improved sensitivity. The microwave sensor based on the asymmetric resonator can be flexibly tailored to design requirement by varying the asymmetry parameter or the topological structure of the resonator. The asymmetric metamaterial resonator-assisted microwave sensor will have potential applications in biosensor and chemosensor fields for sensing minute amounts of dielectric sample substance.

scholarly journals Fabry–Perot Cavity Sensing Probe with High Thermal Stability for an Acoustic Sensor by Structure Compensation

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3393 ◽  
Author(s):  
Jin Cheng ◽  
Yu Zhou ◽  
Xiaoping Zou
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Cavity Length ◽  
High Reliability ◽  
Simple Approach ◽  
High Thermal Stability ◽  
Acoustic Sensor ◽  
Practical Applications ◽  
Fabry Perot ◽  
Expansion Model

Fiber Fabry–Perot cavity sensing probes with high thermal stability for dynamic signal detection which are based on a new method of structure compensation by a proposed thermal expansion model, are presented here. The model reveals that the change of static cavity length with temperature only depends on the thermal expansion coefficient of the materials and the structure parameters. So, fiber Fabry–Perot cavity sensing probes with inherent temperature insensitivity can be obtained by structure compensation. To verify the method, detailed experiments were carried out. The experimental results reveal that the static cavity length of the fiber Fabry–Perot cavity sensing probe with structure compensation hardly changes in the temperature range of −20 to 60 °C and that the method is highly reproducible. Such a method provides a simple approach that allows the as-fabricated fiber Fabry–Perot cavity acoustic sensor to be used for practical applications, exhibiting the great advantages of its simple architecture and high reliability.

Controlling the interference between localized and delocalized surface plasmons via incident polarization for optical switching

2018 ◽  
Vol 32 (16) ◽  
pp. 1850194
Author(s):  
Wen-Bo Song ◽  
Yun Qi ◽  
Xiao-Peng Zhang ◽  
Ming-Li Wan ◽  
Jinna He
Keyword(s):  
Surface Plasmons ◽  
Optical Switching ◽  
Electromagnetically Induced Transparency ◽  
Ground Plane ◽  
Photonic Devices ◽  
Biochemical Sensors ◽  
Optical Responses ◽  
Surface Enhanced Raman ◽  
Induced Transparency ◽  
Incident Polarization

Surface plasmons supported by various metallic nanostructures have given rise to several significant breakthroughs in the field of integrated photonic devices due to its ability to effectively confine and enhance optical field in subwavelength volume. In particular, the demand to actively control optical responses of plasmonic systems becomes urgent for the miniaturization of signal processing devices, surface-enhanced Raman scattering (SERS) substrates and biochemical sensors. In this paper, we systematically investigate the plasmon modes as well as their interaction in a layered nanostructure composed of a periodically-arranged radiative nanoring and a metallic ground plane, as well as a thin insulating spacer. A tunable transparent peak on the background of the broadband plasmon resonance emerges in the reflection spectrum as changing the periodicity of nanoparticle array, a plasmonic analogue of electromagnetically induced transparency (EIT). Owing to the structural symmetry of the rings, we demonstrate a new scheme of controlling the interference between localized and delocalized plasmons by means of incident polarization and believe that the proposed metasurface may find applications in optical switching if the polarization-controlled components are introduced.

scholarly journals Two-Parameter Elliptical Fitting Method for Short-Cavity Fiber Fabry–Perot Sensor Interrogation

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 36 ◽  
Author(s):  
Xiongxing Zhang ◽  
Wei Wang ◽  
Haibin Chen ◽  
Ying Tang ◽  
Zhibo Ma ◽  
...  
Keyword(s):  
White Light ◽  
Cavity Length ◽  
Processing Method ◽  
Light Sources ◽  
Fitting Method ◽  
Data Processing Method ◽  
Fabry Perot ◽  
Gap Sensors ◽  
Two Parameter ◽  
Better Than

To solve the cavity interrogation problem of short cavity fiber Fabry–Perot sensors in white light spectral interrogation with amplified spontaneous emissions (ASEs) as the white light sources, a data processing method, using an improved elliptical fitting equation with only two undetermined coefficients, is proposed. Based on the method, the cavity length of a fiber Fabry–Perot sensor without a complete reflection spectrum period in the frequency domain can be interrogated with relatively high resolution. Extrinsic fiber Fabry–Perot air-gap sensors with cavity lengths less than 30 μm are used to experimentally verify the method, and are successfully interrogated with an accuracy better than 0.55%.

scholarly journals Cryogenic servo-stabilized Fabry-Perot interferometers for imaging at 3-5 and 8-13 microns

1995 ◽  
Vol 149 ◽  
pp. 60-68
Author(s):  
N. K. Reay ◽  
K.A.R.B. Pietraszewski
Keyword(s):  
Response Time ◽  
Spectral Region ◽  
Feedback Loop ◽  
Tuning Range ◽  
Cavity Length ◽  
Operating Temperature ◽  
Piezoelectric Actuators ◽  
Servo Control ◽  
Fabry Perot ◽  
Mirror Spacing

AbstractThe performance of a new liquid Nitrogen cooled Fabry-Perot etalon for imaging at 3-5µm is described. Capacitance sensors monitor the etalon mirror spacing and parallelism, and error signals produced as a consequence of changes in these parameters are used in a feedback loop with piezoelectric actuators for active cavity control. These new cryogenic etalons are designed to be compatible with the Queensgate Instruments Ltd CS100/ET servo-stabilized Fabry-Perot system.The cryogenic etalon has a clear aperture of 50mm and a nominal mirror spacing of between 5 and 60µm. It is coated for the 3 - 5µm spectral region, although coatings are also available for the 2 - 2.5µm and 8 - 13µm regions. Under servo-control at operating temperature the etalon has a response time of 30 msec and a minimum cavity tuning range of ±3µm about the nominal cavity length, corresponding to approximately 3 orders of interference at the midrange wavelength of 4µm.

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