A5004307938- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Photonic Crystal and Fiber Optics
- Analytical Chemistry and Sensors
- Semiconductor Lasers and Optical Devices
- Surface Roughness and Optical Measurements
- Spectroscopy and Laser Applications
- Gas Sensing Nanomaterials and Sensors
- Plasmonic and Surface Plasmon Research
- Magneto-Optical Properties and Applications
- Advanced Sensor and Control Systems
- Optical Coatings and Gratings
- Optical Polarization and Ellipsometry
- Optical Wireless Communication Technologies
- Laser Material Processing Techniques
- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Advanced Measurement and Detection Methods
- Ocular and Laser Science Research
- Calibration and Measurement Techniques
- Porphyrin and Phthalocyanine Chemistry
- Random lasers and scattering media
- Organic Light-Emitting Diodes Research
- Chalcogenide Semiconductor Thin Films
University of Shanghai for Science and Technology
2016-2025
Shanghai University
2001-2011
Shanghai Institute of Optics and Fine Mechanics
1999-2003
Chinese Academy of Sciences
2000
The novel long-period fiber grating (LPFG) film sensor is composed of the coated with solgel-derived sensitive films. characteristics transmissivity LPFG are studied. By analyzing relation among sensitivity Sn, thin optical parameters, and optimal design parameters obtained. Data simulation shows that resolution refractive index this predicted to be 10(-8). Experimentally, a for detection C(2)H(5)OH was fabricated, preliminary gas-sensing test performed.
This paper presents a smart design way for the long-period fiber grating (LPFG) refractive index sensor, which is based on high sensitivity of LPFG near phase-matching turning point (PMTP) to surrounding (SRI). On basis coupled mode theory LPFG, cladding etching and film coating have opposite effects shift dual peaks. Therefore, an can be controlled by successively, until it operates PMTP. Experimentally, operating PMTP was fabricated, glycerol solution concentration monitoring test...
The design of a novel scheme long-period fiber grating (LPFG) film sensor is presented. composed coated with sol–gel derived films, which are sensitive to the surrounding medium (gases). Based on coupled-mode theory, four-layered numerical model has been developed study characteristics transmissivity LPFG sensor. By analyzing relationship between sensitivity Sn and thin optical parameters (thickness h3 refractive index n3) (the period Λ, core change σ length L), optimal can be obtained. Data...
A new, to the best of our knowledge, type liquid level sensor with π -phase-shifted long-period fiber grating operating near phase-matched turning point is proposed. The introduces a -phase shift at center grating, which can generate three attenuation peaks due mode interference effect in transmission spectrum points. According different and temperature sensing characteristics peaks, simultaneous detection be realized through wavelength modulation intensity detection. In this paper,...
An integrated all-fiber sensor based on ring-core fiber (RCF)-embedded long-period grating (LPFG) cascaded RCF-Mach-Zehnder interferometer (MZI) for measuring curvature and temperature is proposed demonstrated experimentally. The RCF-embedded LPFG section fabricated by periodically embedding hundreds of micrometers sized RCF into SMF employing the mature, low-cost cleaving splicing method (CSM). Due to large core diameter mismatch, energy within exceeded cladding mode more effectively,...
A novel few-mode long-period fiber grating (FM-LPFG) sensor based on dual-peak resonance near the phase-match turning point (PMTP) for simultaneous detection of surrounding refractive index (SRI) and temperature is proposed. The PMTP FM-LPFG analyzed coupled-mode theory. cladding modes adjacent order exhibit single-peak resonances in wavelength band 1450–1850 nm, respectively. And response characteristics different resonant peaks to SRI are discussed. Results numerical simulations...
Based on the demand for monitoring conductivity, temperature, and depth (CTD) in ocean, a hybrid coated long-period fiber grating, tilted Bragg grating (LPG-TFBG-FBG) structure is proposed, which could eliminate mutual interference of CTD measurements. First, according to coupled mode theory phase matching conditions, coupling equation each segment deduced. Next, through difference iterative method, total transfer matrix LPG-TFBG-FBG obtained. Then, improve sensitivity make demodulation more...
This letter presents a high-sensitivity wavelength-modulated liquid level sensor based on the long-period fiber grating with superimposed dual-peak. The has novel sensing mechanism and simple structure. In theory, of is analyzed in detail. Experimentally, we fabricated according to simulated parameters. experimental results show linear range 57% length overall yields sensitivity 10.7-nm change wavelength per millimeter, 17 times higher than traditional grating-based sensors.
We reported a long period grating (LPG) written in specially designed photonic crystal fiber (PCF) for refractive index (RI) sensing by interrogating the transmitted light power. The outermost ring of clad holes PCF is enlarged where analyte filled. showed that leakage loss mode increases with RI larger holes. By numerically analyzing complex couple equations core and first mode, we found depth attenuation band spectra total power sensitive to or also demonstrated even less than silica,...
A cascaded long-period fiber grating (CLPFG) sensor with film coating is presented. Two gratings (LPFGs) are to form a Mach-Zehnder interferometer. The optical transmission spectrum and the sensing characteristics for ambient refractive index (RI) measurement of CLPFG analyzed in transfer matrix based on rigorous coupled-mode theory. results indicate that it highly sensitive RI surrounding RI, so can be used as gas or solution sensor. Data simulation shows resolution films predicted 10 −7 ....
In this paper, a novel, to the best of our knowledge, ultra-broadband all-fiber filter is proposed and designed, which composed two (or more) continuously tilted long-period fiber gratings (TLPFGs) with different grating tilt angles same actual period. For constructed TLPFGs, one TLPFG operated in dual-peak resonance state produce peaks, other at phase-matched turning point broadband peak. The three peaks are superimposed, resulting large Based on mode coupling theory, effects structural...
The intensity interrogation of a sensitive-film-coated long-period fibre grating (LPFG) operating near the phase-matching turning point (PMTP) is fully investigated. coated LPFG designed to operate PMTP and little off resonance by properly selecting film parameters; variation refractive index induced interaction between sensitive surrounding medium leads change coupling strength with fixed resonant wavelength. Based on coupled-mode theory four-layer model, property influence optical...
We propose an ultra-broadband apodized chirped long period fiber grating (CLPFG) filter based on phase matching turning point. An with efficiency of ~100% can be obtained under a small change, which overcomes the conflict between chirp coefficient and length. The spectrum this CLPFG is symmetrical, hard to achieve for traditional filters. operates at single cladding mode, so it will not interfered by any other modes. For reducing fluctuations attenuation band filter, use Tanh Gaussian...
Based on the coupled-mode theory, temperature and bending sensing properties of cascaded long-and short-period grating (CLBG) are analyzed by using transfer matrix method. Two resonance peaks produced in reflection spectrum CLBG when wavelengths two gratings approximately equal. The shift along longer wavelength as increases, peak reflectivity at decreases monotonically same time. When is bent, increases evenly while remain unchanged. This tells us that can be used to sense simultaneously....