- 标题
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- 实验方案
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Multi-parameter sensor based on single Long Period Grating in Panda fiber for the simultaneous measurement of SRI, temperature and strain
摘要： In this work, a three-parameter sensor for the simultaneous measurement of surrounding refractive index (SRI), temperature and strain is presented. It is based on a single Long Period Grating (LPG) written in a polarization-maintaining Panda fiber, by means of a simple technique based on Electric Arc Discharge. For the purpose, it is performed the monitoring of the wavelength shift of three different resonances, each one associated to a different cladding mode. Moreover, the set of resonances is acquired for two polarizations of the input light, i.e. aligned to the slow and fast axis of the fiber. The three-parameter sensing is promoted by the fact that the resonance dips show different sensitivities to SRI, temperature and strain, which change their magnitudes and signs when the polarization is switched. It was demonstrated that the sensor can be applied to simultaneously measure SRI in range 1.33–1.40, temperatures comprised in 20–60 °C, and strain of hundreds of με. This device could find application in the fields of materials science and structural health monitoring.
关键词： Refractive index sensor,Temperature sensor,Fiber grating sensor,Strain sensor,Multi-parametric sensor,Long period grating
更新于2025-11-28 14:24:03
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A fast interrogation system of FBG sensors based on low loss jammed-array wideband sawtooth filter
摘要： In this paper, a low loss jammed-array wideband sawtooth (JAWS) filter is built based on a finite reflection virtually imaged array (FRVIA) which has a lower reflectivity of the exit surface compared to a virtually imaged phased array (VIPA). This filter can be used as an edge filter to interrogate the fiber Bragg grating (FBG) sensors. A fast FBG sensing system is set up to detect the strain wave of iron pipe to demonstrate the use of this interrogator. The result shows that the JAWS based interrogation system has advantages of high speed, low loss and high sensitivity.
关键词： JAWS filter,Fiber Bragg grating (FBG) interrogator,Finite reflection virtually imaged array
更新于2025-11-28 14:24:03
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Switchable multi-wavelength and tunable wavelength spacing erbium-doped fiber laser based on a phase-shifted fiber Bragg grating combined with a Mach-Zehnder interferometer
摘要： A switchable multi-wavelength fiber laser with tunable wavelength spacing is proposed. It is based on a structure filter composed of a phase-shifted fiber Bragg grating (PSFBG) and a Mach-Zehnder interferometer (MZI), and the MZI is fabricated by splicing a section of polarization-maintaining fiber with two segments of multi-mode fibers. By adjusting the variable optical attenuator in the cavity and slightly changing the temperature, stable single-, dual-, triple- and quadruple-wavelength emissions can be obtained. The minimum wavelength spacing of adjacent peaks is 0.176 nm, and the maximum is 17.86 nm. The laser line emissions can be switched from 1527.684 nm to 1550.224 nm with optical signal to noise ratio of more than 50 dB. The maximum wavelength fluctuation of the fiber laser is less than 0.025 nm over 50 min. When the strain applied to the filter is changed, the tunable wavelength spacing can be achieved. The wavelength spacing of dual-wavelength laser can be continuously tuned from 21.82 nm to 22.69 nm by applying strain of 0–258 με to the filter.
关键词： Tunable,Switchable multi-wavelength,Phase-shifted fiber Bragg grating,Fiber laser
更新于2025-11-28 14:24:03
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - CO<inf>2</inf> Laser Inscribed Helical Long-Period Grating in Six-Mode Fiber
摘要： We fabricated the helical long-period fiber grating in a six-mode fiber with CO2 laser. The grating realize mode conversion from LP01 mode to LP21 mode with high efficiency. The mode coupling and sensing characteristics are investigated.
关键词： six-mode fiber,Helical long-period grating,mode converter
更新于2025-11-28 14:24:03
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Dispersion independent mode-locked erbium-doped fiber laser with a chirped fiber Bragg grating
摘要： We propose and demonstrate a dispersion-independent erbium-doped mode-locked fiber laser by incorporating a chirped fiber Bragg grating (CFBG) into the laser cavity. Our experimental results show that the fiber laser has similar output characteristics, no matter which section of the CFBG is connected to the laser cavity through a circulator, i.e., opposite dispersion is introduced into the laser cavity. Dispersion independent feature is attributed to the relatively large nonlinearity of the laser cavity with certain bandwidth. This enriches the laser dynamics and provides a new idea for the design of new lasers.
关键词： mode-locked,fiber laser.,Chirped fiber Bragg grating
更新于2025-11-28 14:24:03
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Investigation of narrow band random fiber ring laser based on random phase-shift Bragg grating
摘要： A random ?ber laser based on a 25 mm long random phase-shift ?ber Bragg grating with a ring cavity is experimentally demonstrated in this paper. The random phase-shift grating is fabricated with the beam-scanning method in a single-mode ?ber. The random feedback and light localization are achieved by introducing 20 phase-shift points with random amplitudes along the grating length. A narrow band single-wavelength random ?ber laser with the 3 dB bandwidth of 0.44 pm is realized with a 980 nm laser pumping at 130 mW. The optical signal-to-noise ratio up to 55 dB is obtained at the same pump power. The pump threshold is only 21.8 mW. The number of emitted wavelengths is changeable by adjusting the pump power. The lasing wavelength near 1549.96 nm presents a maximum ?uctuation range of only 1.1 pm over time. With the random grating exposed to water, the mode competition is suppressed and the laser can be operated at more stable single-wavelength mode.
关键词： Laser mode,Ring cavity,Grating,Optical ?ber laser
更新于2025-11-28 14:24:03
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Graphene Heterostructure Integrated Optical Fiber Bragg Grating for Light Motion Tracking and Ultrabroadband Photodetection from 400 nm to 10.768 μm
摘要： Integrated photonics and optoelectronics devices based on graphene and related 2D materials are at the core of the future industrial revolution, facilitating compact and flexible nanophotonic devices. Tracking and detecting the motion of broadband light in millimeter to nanometer scale is an unfold science which has not been fully explored. In this work, tracking and detecting the motion of light (millimeter precision) is first demonstrated by integrating graphene with an optical fiber Bragg grating device (graphene-FBG). When the incident light moves toward and away from the graphene-FBG device, the Bragg wavelength red-shifts and blue-shifts, indicating its light motion tracking ability. Such light tracking capability can be further extended to an ultrabroad wavelength range as all-optical photodetectors show the robust response from 400 nm to 10.768 μm with a linear optical response. Interestingly, it is found that graphene-Bi2Te3 heterostructure on FBG shows 87% higher photoresponse than graphene-FBG at both visible and telecom wavelengths, due to stronger phonon-electron coupling and photo-thermal conversion in the heterostructure. The device also shows superior stability even after 100 d. This work may open up amazing integrated nanophotonics applications such as astrophysics, optical communication, optical computing, optical logic gating, spectroscopy, and laser biology.
关键词： 2D materials,graphene,ultrabroadband photodetection,heterostructures,optical fiber Bragg grating,light motion tracking
更新于2025-11-28 14:24:03
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On-line Writing of Fiber Bragg Grating Array on a Two-mode Optical Fiber for Sensing Applications
摘要： On-line fabricated fiber Bragg grating (FBG) array and its sensing potentials have attracted plenty of attention in recent years. In this paper, FBG arrays are written on-line on a two-mode fiber, and this two-mode fiber Bragg grating (TM-FBG) is further experimentally investigated for temperature and curvature sensing. The responses of this sensor were characterized by 11.2 pm/°C for temperature and ?0.21 dB/m?1 for curvature, respectively. Based on the measurements, a dual-parameter fiber sensing system was developed, which can realize the quasi-distributed, simultaneous detection of temperature and curvature, making it suitable for structural health monitoring or perimeter security.
关键词： on-line grating writing,fiber Bragg grating,two-mode fiber,curvature sensing,temperature sensing
更新于2025-11-28 14:23:57
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Narrow linewidth DBR laser based on high order Bragg grating defined by i-line lithography
摘要： In order to obtain narrow linewidth semiconductor laser around 1564 nm, we design a distributed Bragg reflector (DBR) laser with high-order Bragg gratings (HOBGs) using butterfly encapsulation. The DBR laser is fabricated only by i-line lithography technology with grating period of 4.84 μm, groove width of 1.5 μm and grating length of 72 μm on a strip width of 4 μm. The 1mm-long devices achieved an output power of 9.9 mW and a side mode suppression ratio (SMSR) more than 30 dB without facet coating at an injection current of 80 mA. The lasers showed ultra-narrow Lorentz linewidth of 70 KHz. This paper provides a simple method for large-scale production of narrow linewidth semiconductor lasers.
关键词： narrow linewidth spectrum,Semiconductor laser,high-order grating,distributed Bragg reflector laser
更新于2025-11-28 14:23:57
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Narrow-line InGaN/GaN green laser diode with high-order distributed-feedback surface grating
摘要： We demonstrate narrow-line green laser emission at 513.85 nm with a linewidth of 31 pm and side-mode suppression ratio of 36.9 dB, operating under continuous-wave injection at room temperature. A high-order (40th) distributed-feedback surface grating fabricated on multimode InGaN-based green laser diodes via a focused ion beam produces resolution-limited, single-mode lasing with an optical power of 14 mW, lasing threshold of 7.27 kA cm?2, and maximum slope efficiency of 0.32 W A?1. Our realization of narrow-line green laser diodes opens a pathway toward efficient optical communications, sensing, and atomic clocks.
关键词： InGaN/GaN,green laser diode,distributed-feedback,narrow-line,surface grating
更新于2025-11-28 14:23:57