A5101816174- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Photonic Crystal and Fiber Optics
- Advanced Fiber Laser Technologies
- Magneto-Optical Properties and Applications
- Advanced Photonic Communication Systems
- Semiconductor Lasers and Optical Devices
- Optical Network Technologies
- Power System Optimization and Stability
- Terahertz technology and applications
- Advanced Antenna and Metasurface Technologies
- HVDC Systems and Fault Protection
- Transition Metal Oxide Nanomaterials
- High-Voltage Power Transmission Systems
Beijing Jiaotong University
2016-2019
A magnetic field sensor using a dual-frequency optoelectronic oscillator (OEO) incorporating cascaded magnetostrictive alloy-fiber Bragg grating-Fabry Perot (MA-FBG-FP) and FBG-FP filters is proposed demonstrated. In the OEO resonant cavity, two microwave signals are generated, whose oscillation frequencies determined by filter MA-FBG-FP with ultra-narrow notches laser sources. Due to characteristics of MA FBG, generated show different temperature sensitivities. By monitoring variations...
A novel D-shaped fiber structure combined with a Bragg grating for refractive index (RI) and temperature sensing is proposed experimentally investigated. Thanks to the etched cladding of fiber, resulting interference strongly influenced by surrounding index. By monitoring dip wavelength structure, can be measured. Theoretical analysis simulations were conducted investigate mode propagating behavior RI. Combined property (FBG), possibility simultaneously measuring RI relies on resonance modal...
A novel coreless-D-shape-coreless (CDC) fiber structure for liquid-level sensing is proposed and experimentally investigated. The D-shape with cladding partially etched sensitive to the ambient refractive index change CDC transmission dip wavelength shifts related length of immersed in liquid, so liquid level measured by monitoring wavelength. sensitivities three different liquids RIs 1.333, 1.355, 1.377 are 191.89, 208.11, 213.80 pm/mm, respectively. temperature influence also studied....
Polarization-maintaining terahertz (THz) fibers have been considered as fundamental elements in polarization sensitive THz systems. Based on the anti-resonant waveguiding mechanism, we propose a low-loss polarization-maintaining hollow-core fiber with four half-elliptical cladding membranes. Numerical simulations indicate that birefringence of mode group could be introduced by modifying thickness pair membranes while sacrificing available bandwidth. We observe core size, dimension and shape...
In this letter, we propose and experimentally demonstrate an optical fiber structure sensor using Fabry-Perot interference for temperature pressure measurement. The head consists of incident single-mode fiber, a section capillary pure silica tube, refractive index matching fluid. measurement cavity length change with different has been achieved by monitoring the wavelength shift pattern in reflection spectra. For small scale, sensitivity is 6.95 nm/°C estimated 0.15 nm/Pa. advantages high...
We propose a novel M-shaped single mode fiber (M-SMF) sensor based on stimulated Brillouin scattering of higher-order acoustic modes for simultaneous temperature and strain measurement. Numerical investigation longitudinal in the M-SMF shows that multi-peak spectrum is contributed by couplings between LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> optical multiple modes. The characteristics are compared with those standard fiber....
We propose a novel polarization-maintaining supermode fiber containing quasi-elliptically arranged high-index cores. Numerical simulation indicates that such could support up to 20 distinct modes with different polarization states and spatial orientations. At 1550 nm, all the are separated from their adjacent effective refractive differences beyond 10- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> . also investigate influence of...
We propose a terahertz (THz) hollow-core photonic bandgap fiber (HC-PBGF) supporting few-mode operation with large birefringence. The periodic arrangement of square lattice round corners in cladding offers guidance. Numerical simulation indicates that 21-cell HC-PBGF could support six vector modes the bandgap. Characteristics guided are comprehensively investigated, suggesting modal confinement loss order 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
A kind of stable, switchable and tunable erbium-doped fiber ring laser based on a Sagnac interferometer (SI) is presented experimentally demonstrated. The SI composed section an elliptical-core spun sandwiched between two polarization controllers (PCs) in loop. proposed compound comb filter, which consists cascaded with phase shifted Bragg grating, developed to suppress the mode competition oscillation. By adjusting PCs, stable single-wavelength lasing output can be achieved. optical...
Three-layered single mode fibers with a GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and F co-doped inner core are proposed. Stimulated Brillouin scattering properties in the investigated for discriminative sensing of strain temperature. The optical proposed designed to be well compatible those widely used standard fibers. acoustic properties, including effective velocity, frequency shifts, peak gain efficiencies first three...