A5089247780- Spectroscopy and Laser Applications
- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Atmospheric Ozone and Climate
- Advanced Fiber Laser Technologies
- Semiconductor Lasers and Optical Devices
- Atmospheric and Environmental Gas Dynamics
- Solid State Laser Technologies
- Laser Design and Applications
- Photonic Crystal and Fiber Optics
- Analytical Chemistry and Sensors
- Optical Network Technologies
- Advanced Optical Sensing Technologies
- Advanced Chemical Sensor Technologies
- Photorefractive and Nonlinear Optics
- Gas Sensing Nanomaterials and Sensors
- Water Quality Monitoring and Analysis
- Advanced Measurement and Detection Methods
- Advanced Sensor and Control Systems
- Optical Systems and Laser Technology
- Glass properties and applications
- Advanced optical system design
- Infrared Target Detection Methodologies
- Advanced Sensor Technologies Research
- Photoacoustic and Ultrasonic Imaging
Shandong University
2016-2025
Yunnan University
2011-2024
Nanjing University of Posts and Telecommunications
2024
Huaiyin Institute of Technology
2024
Fudan University
2022-2023
Beijing Institute of Technology
2006-2023
Shanghai Clinical Research Center
2023
Huashan Hospital
2022-2023
Shanghai Electric (China)
2023
Shanghai Center for Brain Science and Brain-Inspired Technology
2023
We propose an adaptive algorithm that is a Variational Mode Decomposition (VMD) optimized by the particle swarm optimization (PSO) algorithm, named PSO-VMD. The method selects envelope entropy of last intrinsic mode function (IMF) in VMD as fitness PSO and 1/10 maximum value correlation coefficient between IMFs standard signal threshold coefficient. In processing simulated experimental second harmonic signals, series standards, including same signal, are used to adaptively achieve noise...
We propose a novel denoising method based on empirical mode decomposition (EMD) to improve the signal-to-noise ratio (SNR) for vibration sensing in phase-sensitive optical time domain reflectometry (φ-OTDR) systems. Raw Rayleigh backscattering traces are decomposed into series of intrinsic functions (IMFs) and residual component using an EMD algorithm. High frequency noise is eliminated by removing several IMFs at position without selected Pearson correlation coefficient (PCC). When pulse...
Noise significantly limits the accuracy and stability of retrieving gas concentration with traditional direct absorption spectroscopy (DAS). Here, we developed an adaptively optimized analysis model (AOGAM) composed a neural sequence filter (NSF) retriever (NCR) based on deep learning algorithms for extraction methane information from noisy transmission spectra obtaining corresponding concentrations denoised spectra. The was trained two data sets, including computationally generated one...
We demonstrated a novel trace gas sensing method based on fiber-ring laser intracavity photoacoustic spectroscopy. This spectroscopic technique is merging of spectroscopy (PAS) with cavity for sensitive and all-fiber detection. A transmission-type PAS cell (resonant frequency f0=2.68 kHz) was placed inside the to fully utilize power. The signal excited by modulating wavelength at f0/2 using custom-made fiber Bragg grating-based modulator. used this detect acetylene (C2H2) 1531.6 nm as proof...
A simple composite cavity structure Er³⁺-doped fiber laser was proposed and demonstrated experimentally. The resonant consists of a pair uniform Bragg gratings (FBGs) π-phase shifted FBG. By introducing the FBG into as selective wavelength component, it can increase effective length suppress multi-longitudinal modes simultaneously. narrow linewidth 900 Hz low RIN -95 dB/Hz were obtained. And lasing rather stable with pump power changing. SMRS more than 67 dB. results show that has good...
A novel active fiber loop ring-down gas sensor combined with dual wavelengths differential absorption method is proposed. Two Distributed Feedback Laser Diodes (DFB LDs) different are employed. One LD whose wavelength covered the line of target used for sensing. Another centered outside reference. The loss can be obtained by differencing reference signal and sensing signal. Compared traditional one employed, it eliminate influence cavity variety photoelectric device drift in system...
We proposed a new method for gas detection in photoacoustic spectroscopy based on acousto-optic Q-switched fiber laser by merging transmission PAS cell (resonant frequency f₀ = 5.3 kHz) inside the cavity. The Q-switching was achieved an modulator, achieving peak pulse power of ~679 mW case modulation signal with optimized duty ratio 10%. used custom-made Bragg grating central wavelength 1530.37 nm (the absorption C₂H₂) to select wavelength. system linear response (R² 0.9941) concentration...
This paper proposed and demonstrated an improved wavelet transform modulus maxima (WTMM) denoising method to decrease the temperature error without decreasing spatial resolution in Raman distributed sensors. In this scheme, WTMM were obtained by combining those on high low decomposition scales, signal was reconstructed using WTMM. Experimental results show that new has better effect than conventional one, allowing for reduction of ~2 °C at 30 60 comparing original data.
A curvelet denoising method has been proposed to reduce the time domain noise improve detection performance in distributed fiber vibration sensing system based on phase-sensitive optical reflectometry. The raw Rayleigh backscattering traces are regarded as a gray image and random can be eliminated by transform; hence, amplitude difference induced external extracted. of event with 10 m spatial resolution along 4 km single mode is demonstrated. signal-to-noise ratio (SNR) location information...
A photodetector with a commercial quartz tuning fork (QTF) based on photothermal effect was demonstrated. Unlike the commonly used thermosensitive elements, QTF mechanical resonance ability and piezoelectric to amplify signal. Operating at optimal operating distance modulation signal duty ratio selected for photodetector, achieved good linear response wavelength of 1550 nm 980 nm. And photoresponsivity reach up 515 mV/mW More important, detection sensitivity 0.75 pW 203 s integration time...
A highly efficient extracavity Raman laser pumped by the infrared nanosecond pulses is presented utilizing recently recommended medium-strontium tungstate crystal (SrWO/sub 4/). The maximum conversion efficiency of first and second Stokes both reached about 50%, total was obtained to be 70% in experiment. dependence on polarization temporal characteristics pump were also studied. theoretical model for solid-state established based radiation transfer equations describing stimulated scattering...