- 标题
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- 实验方案
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Tunable single-longitudinal-mode fiber laser based on a chirped fiber Bragg grating
摘要： In this paper, a tunable single-longitudinal-mode (SLM) fiber laser based on a chirped fiber Bragg grating (CFBG) is proposed and experimentally demonstrated. Multi-sub-cavities formed by a single CFBG inserted inside the laser loop greatly increase the longitudinal mode spacing so that SLM operation can be obtained. The SLM laser output can be tuned in a wide wavelength range from 1535 to 1565 nm by simply adjusting the central wavelength of a tunable optical band-pass filter (TOBF). A side-mode suppression ratio of larger than 50 dB and a linewidth of less than 8.5 kHz have been respectively achieved.
关键词： Single-longitudinal-mode (SLM),Fiber laser,Chirped fiber Bragg grating (CFBG)
更新于2025-09-11 14:15:04
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Effect of Temperature and Gamma-Ray Irradiation on Optical Characteristics of Fiber Bragg Grating Inscribed Radiation-Resistant Optical Fiber
摘要： A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating (FBG) under γ-ray irradiation environment. The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18 ℃ to 40 ℃ before the γ-ray irradiation were about 4.57×10–4 dB/℃ and 5.48 pm/℃, respectively. The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under the γ-ray irradiation with the total dose of 22.85 kGy at 35 ℃ were about 0.03 dB/m and 0.12 nm, respectively, with the γ-ray irradiation sensitivity of 5.25×10–3 pm/Gy. The temperature and the γ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18 ℃ to 40 ℃ and the γ-ray irradiation with the total dose of 22.85 kGy at 35 ℃, respectively. Furthermore, the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of the γ-ray irradiation. However, no influence on the reflection power of the Bragg wavelengths and the full width at half maximum (FWHM) bandwidth under temperature and the γ-ray irradiation change was found. Also, after the γ-ray irradiation with the dose of 22.85 kGy, no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.
关键词： Optical fiber,radiation-induced attenuation,fiber Bragg grating,temperature sensor,radiation resistance
更新于2025-09-11 14:15:04
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Nonuniform Microwave Photonic Delay-Line Filter For Optical Sensor Network Interrogation
摘要： We propose a new design of nonuniform spaced microwave photonic delay-line filter based generic optical fiber sensors interrogation platform. Both the amplitude and phase response of the microwave filter are used to demodulate optical sensors. Therefore, a large sensor network with different types of optical sensors can be interrogated simultaneously. The concept of this new microwave photonics enabled interrogation approach is presented and verified by simulations where four different types of optical sensors are simultaneously interrogated via inverse Fourier transform of filter frequency response.
关键词： time delay,fiber Bragg grating,microwave photonics,finite impulse response,Fourier transform,optical sensors
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Photonics Conference (IPC) - San Antonio, TX, USA (2019.9.29-2019.10.3)] 2019 IEEE Photonics Conference (IPC) - Optical Sensor Behavior Prediction using LSTM Neural Network
摘要： Optical fiber-based-sensors proved capable of enduring various harsh environments. Long-short-term memory (LSTM) neural-networks are often used for datasets with long- dependences. Here, rare FBG measurements collected from a neutron reactor core were used to build a neural-network capable of predicting the future events inside the reactor.
关键词： Fiber Bragg grating,nuclear reactor core measurements,long-short-term memory,recurrent neural networks
更新于2025-09-11 14:15:04
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Femtosecond Laser Inscribed Sapphire Fiber Bragg Grating for High Temperature and Strain Sensing
摘要： In this paper, a sapphire fiber Bragg grating (SFBG) is fabricated by femtosecond (fs) laser line-by-line scanning method. A third-order fiber Bragg grating is obtained in a single crystal sapphire fiber with a diameter of 60 μm. Compared to the SFBG written by point-by-point method, the SFBG written by the line-by-line method has a higher reflectivity and grating with about 15% reflectivity is achieved when the track length is about 40 μm. The temperature sensing characteristics of this SFBG from room temperature to 1600°C are studied, and the temperature sensitivity of SFBG is 34.96 pm/°C from 1000°C to 1600°C. The strain characteristics are also tested at the temperature of 26°C, 500°C, 1000°C and 1600°C, and the strain sensitivities are 1.42 pm/με, 1.42pm/με, 1.44 pm/με and 1.45 pm/με, respectively. These characteristics show that this SFBG has potential applications in harsh environment structural health monitoring.
关键词： structural health monitoring,femtosecond laser,line-by-line scanning,Sapphire fiber Bragg grating
更新于2025-09-11 14:15:04
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[IEEE 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Hyderabad (2017.12.18-2017.12.19)] 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Asymmetric-Pulse Shaping Technique Using Fiber Bragg Grating
摘要： We report a novel optical pulse shaping technique for generating a reverse sawtooth pulse from an optical gaussian pulse using a linearly chirped fiber Bragg grating. We have carried out simulations with gaussian pulses of order 2, 4 and 8 and the results show that asymmetry of the reflected pulse increases with the order of input gaussian pulse.
关键词： Fiber Bragg grating,Reverse sawtooth,Pulse shaping
更新于2025-09-11 14:15:04
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Research on high resolution fiber Bragg grating sensing technology based on high speed parallel sampling
摘要： The high resolution fiber Bragg sensing system based on high speed parallel sampling technology is proposed. According to the Rayleigh criterion, it is generally believed that the number of the measured data of the fiber grating reflection spectrum is limited to the resolution of the wavelength measurement device. So, in order to achieve high spectral resolution, high resolution wavelength measurement devices, at the same time, to achieve small variations of the transmission wavelength of the Fabry–Perot (FP) filter, the high bit digital-to-analog converter (DAC) was adopted to generates small step drive voltages, these will greatly increase the cost of the system. However, in this paper, the fiber Bragg sensing system with the low resolution FP filter and low bit DAC achieves the high resolution wavelength measurement by using the high speed parallel sampling. In addition, the resolution of wavelength in fiber grating sensing system is analyzed theoretically.
关键词： Parallel sampling technology,Wavelength resolution,Fiber Bragg grating,Optical fiber sensing
更新于2025-09-10 09:29:36
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An optical soft-sensor based shape sensing using a bio-inspired pattern recognition technique to realise fly-by-feel capability for intelligent aircraft operation
摘要： Information regarding deformations in large and complex systems is necessary in the prediction of structural failures caused by un-natural flexural occurrences. Sensing systems which are used to predict shapes, in order to develop a global surface picture require high precision and lower time lag. In this work, a unique bio-inspired training mechanism for support vector regression is presented for shape sensing in structures mounted with Fiber Bragg Gratings. Experimental validation was carried out on a simply supported beam, loaded at different positions and an aircraft wing model for different types of bending. The resulting deflections at specified locations along the length of the beam and on both surfaces of the wing were interpreted from the wavelength shifts of the corresponding Fiber Bragg Gratings through the specially modified Support Vector Regression. The method has shown high accuracy, low computational requirements and enhanced prediction times. The proposed bio-inspired training method has also been compared with two conventional training methodologies.
关键词： Fiber Bragg Grating,Decoding variable,Shape sensing,optical soft-sensor,Bio-inspired multi-target single model,Support vector regression
更新于2025-09-10 09:29:36
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Application of Fiber Bragg Grating Acoustic Emission Sensors in Thin Polymer-Bonded Explosives
摘要： Fiber Bragg grating (FBG) acoustic emission (AE) sensors have been used in many applications. In this paper, based on an FBG AE sensor, the sensing principle of the interaction between the AE wave and the sensor is introduced. Then, the directionality of the FBG AE sensor on the surface of a thin polymer-bonded explosive (PBX) material is studied. Finally, the time coefficient location method is proposed to correct the AE time detected by the FBG AE sensor, thereby improving the accuracy of location experiments.
关键词： directionality,polymer-bonded explosives,time coefficient location method,fiber Bragg grating acoustic emission sensor
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 20th International Conference on e-Health Networking, Applications and Services (Healthcom) - Ostrava, Czech Republic (2018.9.17-2018.9.20)] 2018 IEEE 20th International Conference on e-Health Networking, Applications and Services (Healthcom) - SMART medical polydimethylsiloxane for monitoring vital signs of the human body
摘要： This paper focuses on current trends in non-invasive monitoring of vital functions of the human body using SMART sensors. It describes a sensor pad made of a thin layer of polydimethylsiloxane (PDMS) with one symmetrically positioned fibre Bragg grating (FBG). The PDMS material is immune to electromagnetic interferences (EMI) and inert to human skin. By combining fibre-optic technology and PDMS, the SMART PAD sensor is formed which is used not only for classical hospital environments, but also for electromagnetically interfered environments, for example magnetic resonance imaging (MRI). The basic monitored parameters described are the respiratory rate (RR) and heart rate (HR) of the human body. The results were obtained in a laboratory environment in a group of 10 volunteers upon their written consent. The acquired results were compared by the Bland-Altman (B-A) method, which belongs to the group of statistical methods in biomedical research.
关键词： heart rate,respiratory rate,fiber Bragg grating,vital sign monitoring,polydimethylsiloxane
更新于2025-09-10 09:29:36