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- 实验方案
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Design of a Wide Ranging Highly Sensitive Pressure Sensor Based on Two-Dimensional Photonic Crystals
摘要： A highly sensitive pressure sensor operating over a wide pressure range based on two-dimensional photonic crystals having a Mach-Zehnder interferometer structure has been developed. The plane wave expansion method (PWE) is used to determine the device operating wavelength range. The finite difference time domain method (FDTD) is used to calculate the device characteristic parameters such as the resonant frequency, the power transmission, and the sensitivity. The present sensor has two wide frequency ranges, a high sensitivity to refractive index changes and the highest detectable sensitivity pressure so far reported in the literature, that is, 25.06 nm/GPa. The present device has high and constant transmission power all over the entire pressure range 0 to 10 GPa. This is of practical importance since the constraints imposed on the sensing system (the light source and the photodetector) are the same.
关键词： Power transmission,Sensitivity,Mach-Zehnder interferometer,Pressure sensor,2-D photonic crystals,FDTD
更新于2025-09-23 15:21:21
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Photothermal Effects Induced by Surface Plasmon Resonance at Graphene/Gold Nanointerfaces: A Multiscale Modeling Study
摘要： Surface plasmon resonance (SPR) biosensors have enormous potential in biological recognitions and biomolecular interactions, especially for the real time measurement of disease diagnosis and drug screening. Extensive efforts have been invested to ameliorate the sensing performances, while the photothermal effects, which are induced by the plasmon resonance, have an obvious impact. However, due to the limitations of experimental approaches, the theoretical mechanisms and specific influences of the SPR sensors with photothermal effects are few researched. Here, a multiscale simulation method is developed to investigate the photothermal effects at graphene/gold (Au) nanointerfaces, and to calculate the quantitative contribution of the photothermal effects towards high reliability SPR sensors in order to elucidate their influence on the sensing performances by means of first-principle calculations and molecular dynamics simulations. Our results indicate that the sensitivity and detection accuracy of graphene/Au SPR sensors can be tailored from 0 K to 600 K, due to the tunable dielectric constants of Au and graphene films through temperature variation. By controlling the its material thickness, interfacial combination and lattice strain, an optimized graphene/Au SPR sensor with higher sensitivity, detection accuracy, and reliability to the temperature rising has been achieved. Such multiscale simulation method, which is capable of seeking both the role and the underlying mechanism of the interfacial phenomena, can serve as an excellent guideline for the performance optimization and commercialized application of SPR sensors in the analytical chemistry and biomedical fields.
关键词： graphene/gold nanointerface,photothermal effects,surface plasmon resonance,multiscale simulation method,sensitivity and detection accuracy
更新于2025-09-23 15:21:21
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EFFECT OF SIZE ON SINGLE AND DOUBLE OPTICAL MICROBOTTLE RESONATOR HUMIDITY SENSORS
摘要： An experimental study on the effect of whispering gallery mode (WGMs) on micro-bottle resonator (MBR) and its application on humidity sensing is presented. Different transmission mode spectra observed when the diameter of MBR (Db) change from 130μm to 190μm. The Q-factor for single and double MBRs ware observed > 104 for all cases. The size and number of MBRs effecting Q-factor value which are high Q-factor value for smallest size Db = 130μm for single MBR and Pair-4 (combination of two biggest MBRs Db = 190μm) for double MBRs. Application of single and double MBRs in humidity sensing received various sensing performance. With the highest sensitivity value, linearity >90% and P-value > 10-13 make MBR with diameter 130μm to be the best performance as humidity sensor for all cases. Both single and double MBRs are stable over 60 seconds. Overall, the size of the MBR has been shown to be more important than the quantity of MBRs for humidity sensing. Indeed, double MBRs actually perform worse than single MBRs as humidity sensors.
关键词： Q-factor,Sensitivity,Humidity sensor,Whispering gallery mode,Micro-bottle resonator
更新于2025-09-23 15:21:21
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Terahertz Bragg Resonator based on a Mechanical Assembly of Metal Grating and Metal Waveguide
摘要： The physical contrast sensitivity of microwave imaging systems employing scattering-parameter measurements is defined. Methodologies are proposed for its evaluation through measurements and through simulations. This enables the estimation of the smallest detectable target permittivity contrast or size for the system under evaluation. The outcomes of the proposed simulation-based and measurement-based methods are compared for the case of a realistic tissue-imaging system. The agreement between the simulated and measured sensitivity estimation validates the proposed methods. The intention of the proposed methodology is to provide common means to quantify and compare the sensitivity performance of microwave systems used in tissue imaging as well as the antennas used as sensors. We emphasize that the proposed method targets the performance of the hardware and it is not concerned with the image-reconstruction algorithms.
关键词： microwave imaging,tissue sensing,Antenna measurements,receiver sensitivity,response sensitivity,physical contrast sensitivity (PCS)
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE International Conference on Telecommunications and Photonics (ICTP) - Dhaka, Bangladesh (2019.12.28-2019.12.30)] 2019 IEEE International Conference on Telecommunications and Photonics (ICTP) - Sensitivity Enhanced Surface Plasmon Resonance (SPR) Sensors with MoS <sub/>2</sub> /Graphene Hybrid Overlayer
摘要： A performance enhanced surface plasmon resonance sensor has been designed with a molybdenum disulfide (MoS2)/graphene hybrid overlayer. Atomically thin transition metal dichalcogenide (TMDC) nanomaterials like MoS2 have exhibited better optical and electronic properties in the two-dimensional (2D) scale. The MoS2/graphene hybrid overlayer protects the metal layer of the SPR sensor from undesired oxidation and retains higher sensitivity. As they have large surface to volume ratio and adjustable biocompatibility, the sensor performance increases several times than only graphene based configuration. The proposed SPR sensor includes a titanium (Ti) layer which enhances the adherence level between silver and prism glass. Sensitivity factor (SF), sensor merit (SM), full-width at half-maximum (FWHM) and combined sensitivity factor (CSF) have been used to measure the performance of the proposed sensor. The proposed sensor has the SF of 71.260/RIU and CSF of 372.72 RIU-1, which are much higher than the existing sensor configuration without MoS2 overlayer.
关键词： combined sensitivity factor,SPR sensor,MoS2 / graphene hybrid overlayer,sensitivity factor
更新于2025-09-23 15:21:01
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Quantum Rotation Sensing with Dual Sagnac Interferometers in an Atom-Optical Waveguide
摘要： We describe a Sagnac interferometer suitable for rotation sensing, implemented using an atomic Bose-Einstein condensate confined in a harmonic magnetic trap. The atom wave packets are split and recombined by standing-wave Bragg lasers, and the trapping potential steers the packets along circular trajectories with a radius of 0.2 mm. Two conjugate interferometers are implemented simultaneously to provide common-mode rejection of noise and to isolate the rotation signal. With interference visibilities of about 50%, we achieve a rotation sensitivity comparable to Earth’s rate in about 10 min of operation. Gyroscope operation was demonstrated by rotating the optical table on which the experiment was performed.
关键词： Sagnac Interferometers,Quantum Rotation Sensing,Rotation Sensitivity,Atom-Optical Waveguide,Bose-Einstein Condensate
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Valparaiso, Chile (2019.11.13-2019.11.27)] 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Fourier-Bessel Shapes in Output Photocurrents and Frequency Chirping Effects from Laser Fields
摘要： Record low values in this material system of threshold current density, particularly at elevated temperature, are presented for InP quantum dot lasers. Lasers with Ga0 .5 8 In0 .4 2 P in the dot upper con?ning layer have the lowest threshold current densities, 138 A·cm?2 at 300 K, and 235 A·cm?2 at 350 K (77 °C) (2-mm lasers, uncoated facets). Gain-current density data suggests laser performance with an upper con?ning layer of Gax In1 ?xP with x = 0.54, 0.56 or 0.58 would be similar if not for the very low internal optical mode loss, αi of samples with x = 0.56 and 0.58. Gain measurements at ?xed inversion level suggest that increasing x content in Gax In1 ?xP increases gain at ?xed inversion level but samples with x = 0.54 also exhibit reduced recombination current density. The increasing recombination current density at elevated temperature due to thermal carrier spreading is signi?cantly reduced in samples with x = 0.56 and x = 0.58 but measurements at common operating points attribute this largely to the reduced αi for these samples and given the same αI , samples with x = 0.54, 0.56 and 0.58 would all bene?t from reduced effects due to thermal carrier spreading compared to x = 0.52.
关键词： Quantum dot devices,InP self-assembled quantum dots,semiconductor laser,short wavelength lasers,threshold current density,temperature sensitivity
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America) - Gramado, Brazil (2019.9.15-2019.9.18)] 2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America) - Financial Impact of the Binomial Tariff in the Investment in Residential Photovoltaic Systems
摘要： The design of a sensitivity improved dual diaphragm based vibrating wire transducer for sensing pneumatic pressure is proposed. The improvement achieved in sensitivity of a dual diaphragm structure over the single diaphragm category is veri?ed through experiments. An experimental setup for ef?ciently assessing the dynamic performances of the pressure transducers is presented. Eventually, the improved sensitivity concedes improvement in precision and resolution of the instrument. While the vibrating wire transducer based pressure sensors always show better dynamic performances over others, the present dual diaphragm structure offers improved sensitivity, which adds to their dynamic performances and overall performance characteristics.
关键词： sensitivity improvement,time constant measurement,Diaphragm structure,dynamic pressure sensor
更新于2025-09-23 15:21:01
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Waveguide optimization and its evaluation of a doped polymer optical ???ber designed for visual detection of stress
摘要： A fiber-optic strain sensor using a fluorophore-doped polymer optical fiber (POF) was fabricated at various waveguiding conditions. The effects attributed to each structural feature of the sensor were characterized by observing the sensor?s response. Two fluorophores, Coumarin 540A and Rhodamine 6G, were used to dope the core and the cladding of a poly(methyl methacrylate)-based POF, respectively. Using doped POFs with different numerical apertures (NAs), the changes in the fluorophore peaks upon the application of stress were analyzed by applying macrobending (s) to the fiber. Although the sensor response did not show linearity with respect to the NA, it was found that the shape of the Coumarin 540A-attributed peak was a factor that represented the sensor?s sensitivity. As a result, the double-cladding structure demonstrated its effectiveness in improving the stress sensitivity.
关键词： double-cladding structure,fluorophore-doped,polymer optical fiber,numerical aperture,fiber-optic strain sensor,stress sensitivity
更新于2025-09-23 15:21:01
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Magnetic field sensor based on magnetoplasmonic crystal
摘要： Here we report on designing a magnetic field sensor based on magnetoplasmonic crystal made of noble and ferromagnetic metals deposited on one-dimensional subwavelength grating. The experimental data demonstrate resonant transverse magneto-optical Kerr effect (TMOKE) at a narrow spectral region of 50 nm corresponding to the surface plasmon-polaritons excitation and maximum modulation of the reflected light intensity of 4.5% in a modulating magnetic field with the magnitude of 16 Oe. Dependences of TMOKE on external alternating current (AC) and direct current (DC) magnetic field demonstrate that it is a possibility to use the magnetoplasmonic crystal as a high-sensitive sensing probe. The achieved sensitivity to DC magnetic field is up to 10?6 Oe at local area of 1 mm2.
关键词： sensitivity,surface plasmon-polaritons,transverse magneto-optical Kerr effect,magnetic field sensor,magnetoplasmonic crystal
更新于2025-09-23 15:21:01