scholarly journals High-Sensitivity Cuboid Interferometric Fiber-Optic Hydrophone Based on Planar Rectangular Film Sensing

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6422
Author(s):  
Wenrui Wang ◽  
Yeye Pei ◽  
Lingyun Ye ◽  
Kaichen Song
Keyword(s):  
Fiber Optic ◽  
Simulation Analysis ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Acoustic Detection ◽  
Frequency Range ◽  
Operating Frequency Range ◽  
Important Means ◽  
The Mean ◽  
Theoretical Pressure

Interferometric fiber-optic hydrophones are an important means in the field of underwater acoustic detection. The design of the hydrophone sensor head is the key technology related to its detection sensitivity. In this paper, a high-sensitivity cuboid interferometric fiber-optic hydrophone based on planar rectangular film sensing is proposed, and the sensitivity of the sensor is compared with that of the widely used air-backed mandrel hydrophone under the same conditions. The acoustic characteristic models of the two types of sensors were established by theoretical calculation and simulation analysis to obtain the theoretical pressure sensitivity. Some experiments were performed to examine the theory and design. According to the experiment results, the mean phase sensitivity of the mandrel type was −112.85 dB re 1 rad/μPa in the operating frequency range of 10–300 Hz, and that of the cuboid type was −84.50 dB re 1 rad/μPa. The latter was 28.35 dB higher than the former was. These results are useful for improving hydrophone sensitivity.

scholarly journals 2D Propagation Simulation of Variation Parameters of U-shape Fiber Optic

2020 ◽  
Vol 10 (2) ◽  
pp. 153-158
Keyword(s):  
Fiber Optics ◽  
Power Flow ◽  
Fiber Optic ◽  
Power Transmission ◽  
Simulation Analysis ◽  
Reducing Power ◽  
High Sensitivity ◽  
Curvature Radius ◽  
Sensor Applications ◽  
Core Fiber

Fiber optic has extraordinary properties and is suitable in sensor applications due to its special potential. Currently, macro bending characteristics of newly developed hetero core fiber optic element are designed and evaluated. This paper presents the preliminary results obtained from the numerical simulation analysis of the bending sensitivity of U-shape fiber optics toward the 2D electromagnetic wave in terms of mesh, curvature radius, core fiber size, and turn number. Fiber optics with core sizes of 4, 9, 50, and 62.5 μm were designed. In addition, the combination of core diameters 50-4-50, 50-9-50, 62.5-4-62.5, and 62.5-9-62.5 μm is evaluated to compare the outcome of transmission power in terms of hetero core structure of fiber optic. Simulation is performed using COMSOL Multiphysics simulation tool. The developed U-shape fiber optic is designed to sense the distortion of reducing power transmission by comparing input and output power. Results show that the selected mesh depends on the size of geometry bending fiber optics, and fine and finer mesh is the best for U-shape fiber optic. Furthermore, the power flow on the fiber decreases with the decreasing curvature radius and increasing turn number. The fiber with a core size combination of 62.5–4–62.5 um has high sensitivity in terms of loss. The attained results possess higher potential in the field of sensor applications, such as displacement, strain, pressure, and monitoring respiration, on human body. This study serves as a basis for further investigation of nanomaterial coating on fiber optics, thereby enhancing its credibility for sensing.

Far-ultraviolet Ionospheric Photometer

2020 ◽  
Author(s):  
Ruyi Peng ◽  
Liping Fu
Keyword(s):  
High Sensitivity ◽  
Detection Sensitivity ◽  
Space Environment ◽  
Physical Parameters ◽  
Optical Remote Sensing ◽  
Electronic Density ◽  
Radio Communications ◽  
Important Means ◽  
Far Ultraviolet ◽  
The Impact

<p>As a space-based optical remote sensing method, Far-ultraviolet Ionospheric Photometer with small size, low power consumption, high sensitivity is an important means to detect physical parameters of the ionosphere. Using the Far-ultraviolet Ionospheric Photometer to detect the intensity of ionospheric 135.6nm night airglow can obtain the ionospheric TEC, F2 layer peak electronic density(NmF2), which can be used to study the information on changes in ionospheric space environment,and the impact of the ionosphere on the radio communications, etc.; The ionospheric 135.6nm day airglow and the LBH radiation radiance can be used to obtain the ionospheric O / N2 ratio information, which can be used to study the space weather events and monitor the electromagnetic environment changes in the Earth's space. The FY3-D Ionospheric Photometer(IPM), launched on November 15, 2017, has a detection sensitivity which is greater than 150 counts / s / Rayleigh and a spatial field of view of 1.6 × 3.5 ° with high horizontal spatial resolution that will help to achieve the fine detection of the ionosphere. This report will analyze the FY3-D IPM detection results.At the same time,the report will introduce our research team’s work on the development and application of other payloads in the far ultraviolet band</p>

scholarly journals CMOS Front-End of LNA for GPS and GSM wireless applications

2017 ◽  
Vol 7 (1.5) ◽  
pp. 1
Author(s):  
Mahesh Mudavath ◽  
K. Hari Kishore
Keyword(s):  
Power Dissipation ◽  
Simulation Analysis ◽  
Noise Figure ◽  
Low Cost ◽  
High Sensitivity ◽  
Low Noise ◽  
Frequency Range ◽  
Wireless Applications ◽  
Noise Amplifier ◽  
Intercept Point

This paper describes a layout of a CMOS Low Noise Amplifier for reconfigurable packages which include GPS, GSM Wi-Fi applications. The improvement of a notably linear Radio front-stop, able to function with Galileo and GPS satellite signals suitable for coexisting in a mobile opposed environment for area based offerings, pleasing the fundamental necessities for a mass market product which includes low cost, low footprint, good accuracy, low strength intake and high sensitivity. primarily based on a wideband enter matching, the LNA stages cowl all band of hobby even as reaching a great change-off between excessive gain, low noise parent and coffee electricity intake. The complete simulation analysis of the circuit results in the frequency range of 1.4 GHz to 2 GHz. The noise figure is 1.8 dB at 1.4GHz and rises to 3.4 dB at 2 GHz. The input return and output return losses (S11, S22) of the LNA at a frequency range between 1.4 GHz and 2 GHz are S11= -12 dB, S22 =-44.73 dB at 1.77 GHz and S22 =-26.47 dB at 2 GHz. The overall gain of the LNA (S21) is 13 dB at 1.4025 GHz, 3rd order input intercept point (IIP3) = -3.16 dBm and -1dB compression point is -12.56 dBm. Input Impedance of 50Ω, 3dB Power Bandwidth of 450MHz, and Power Dissipation of 2.7mW at 1.2V power supply.

A novel fiber optic geophone with high sensitivity for geo-acoustic detection

2014 ◽  
Author(s):  
Zhenhui Zhang ◽  
Huayong Yang ◽  
Shuidong Xiong ◽  
Hong Luo ◽  
Chunyan Cao ◽  
...  
Keyword(s):  
Fiber Optic ◽  
High Sensitivity ◽  
Acoustic Detection

Fiber-Optic Distributed Vibration Sensor for Pipeline Pre-Alarm

2014 ◽  
Vol 684 ◽  
pp. 235-239 ◽  
Author(s):  
Wen Tai Lin ◽  
Shu Qin Lou ◽  
Sheng Liang
Keyword(s):  
Time Delay ◽  
Pressure Wave ◽  
Oil And Gas ◽  
Fiber Optic ◽  
High Spatial Resolution ◽  
High Reliability ◽  
High Sensitivity ◽  
Vibration Sensor ◽  
Acoustic Detection ◽  
Wave Detection

Pipeline security is very important in oil and gas transportation. Traditional technology such as negative pressure wave detection, acoustic detection doesn’t match the need of pre-alarm. A fiber-optic distributed vibration sensor (FDVS) is proposed and investigated. It is found that the FDVS has the advantages of long sensing distance, high spatial resolution, high sensitivity, high reliability, etc. According to calculating the time delay of the two MZIs , the vibration can be located.

Features of Thrombi and Diagnostic Accuracy of Impedance Plethysmography in Symptomatic and Asymptomatic Deep Vein Thrombosis

1993 ◽  
Vol 70 (02) ◽  
pp. 266-269 ◽  
Author(s):  
Giancarlo Agnelli ◽  
Benilde Cosmi ◽  
Stefano Radicchia ◽  
Franca Veschi ◽  
Enrico Boschetti ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Diagnostic Accuracy ◽  
High Sensitivity ◽  
Impedance Plethysmography ◽  
Surveillance Programme ◽  
Vein Thrombosis ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
The Mean ◽  
Deep Vein

SummaryImpedance plethysmography (IPG) has high sensitivity and specificity in patients with symptomatic deep vein thrombosis (DVT) while it fails to detect asymptomatic DVT. The aim of this study was to determine whether the features of thrombi such as location, size and occlusiveness could explain the different accuracy of IPG in symptomatic and asymptomatic DVT patients. One-hundred and seventeen consecutive outpatients with a clinical suspicion of DVT and 246 consecutive patients undergoing hip surgery were admitted to the study. In symptomatic patients IPG was performed on the day of referral, followed by venography, while in asymptomatic patients IPG was performed as a surveillance programme, followed by bilateral venography.A venography proved DVT was observed in 37% of the symptomatic patients and 34% of the asymptomatic limbs. A significantly higher proportion of proximal DVTs was found in symptomatic patients than in asymptomatic patients (78% vs 46%; p = 0.001). The mean Marder score, taken as an index of thrombus size, was significantly higher in symptomatic patients than in asymptomatic patients (19.0 vs 9.6; p = 0.0001). A significantly higher proportion of occlusive DVTs was observed in symptomatic than in asymptomatic patients (69% vs 36%; p = 0.001).We conclude that the unsatisfactory diagnostic accuracy of IPG in asymptomatic DVT is due to the high prevalence of distal, small and non occlusive thrombi. Such thrombi are unlikely to cause a critical obstruction of the venous outflow and therefore to produce a positive IPG.

Enhanced Detection Sensitivity with Pulsed Laser Digital Signal Integration Algorithm

2006 ◽  
Author(s):  
A.C.T. Quah ◽  
J.C.H. Phang ◽  
L.S. Koh ◽  
S.H. Tan ◽  
C.M. Chua
Keyword(s):  
Fault Localization ◽  
Pulsed Laser ◽  
Digital Signal ◽  
Detection Sensitivity ◽  
Signal Integration ◽  
Laser Operation ◽  
Frequency Range ◽  
Integration Algorithm ◽  
Detection Systems ◽  
Lock In

Abstract This paper describes a pulsed laser induced digital signal integration algorithm for pulsed laser operation that is compatible with existing ac-coupled and dc-coupled detection systems for fault localization. This algorithm enhances laser induced detection sensitivity without a lock-in amplifier. The best detection sensitivity is achieved at a pulsing frequency range between 500 Hz to 1.5 kHz. Within this frequency range, the algorithm is capable of achieving more than 9 times enhancement in detection sensitivity.

High-sensitivity fiber optic magnetic field sensor based on lossy mode resonance and hollow core-offset structure

2021 ◽  
pp. 1-12
Author(s):  
Xue-Peng Jin ◽  
Hong-Zhi Sun ◽  
Shuo-Wei Jin ◽  
Wan-Ming Zhao ◽  
Jing-Ren Tang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fiber Optic ◽  
High Sensitivity ◽  
Magnetic Field Sensor ◽  
Hollow Core ◽  
Field Sensor

scholarly journals High Sensitivity Continuous Monitoring of Chloroform Gas by Using Wavelength Modulation Photoacoustic Spectroscopy in the Near-Infrared Range

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Continuous Monitoring ◽  
Near Infrared ◽  
Resonant Cavity ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Infrared Range ◽  
Wavelength Modulation ◽  
Linear Coefficient

An optical system for gaseous chloroform (CHCl3) detection based on wavelength modulation photoacoustic spectroscopy (WMPAS) is proposed for the first time by using a distributed feedback (DFB) laser with a center wavelength of 1683 nm where chloroform has strong and complex absorption peaks. The WMPAS sensor developed possesses the advantages of having a simple structure, high-sensitivity, and direct measurement. A resonant cavity made of stainless steel with a resonant frequency of 6390 Hz was utilized, and eight microphones were located at the middle of the resonator at uniform intervals to collect the sound signal. All of the devices were integrated into an instrument box for practical applications. The performance of the WMPAS sensor was experimentally demonstrated with the measurement of different concentrations of chloroform from 63 to 625 ppm. A linear coefficient R2 of 0.999 and a detection sensitivity of 0.28 ppm with a time period of 20 s were achieved at room temperature (around 20 °C) and atmosphere pressure. Long-time continuous monitoring for a fixed concentration of chloroform gas was carried out to demonstrate the excellent stability of the system. The performance of the system shows great practical value for the detection of chloroform gas in industrial applications.

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