- 标题
- 摘要
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- 实验方案
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Wavelength-tunable single-frequency ytterbium-doped fiber laser based on a double-circulator interferometer
摘要： We reported a novel type of wavelength-tunable single-frequency ytterbium-doped fiber laser based on a double-circulator compound cavity and a section of unpumped ytterbium-doped fiber. The multi-longitudinal-mode oscillations are suppressed by the double-circulator structure and the single frequency operation is obtained finally by the standing wave grating in the unpumped ytterbium-doped fiber. The central wavelength of the laser beam is selected by a tunable filter ranging from 1040 nm to 1080 nm. The results show that the side mode suppression ratio in this range is greater than 47 dB and the maximum value is 58 dB at 1070.06 nm. The observed maximum wavelength fluctuation and power variation at 1060 nm are 0.012 nm and 0.22 dB during 1 h, respectively. The mean value of the linewidth in this range is 2.82 kHz and the minimum value of the linewidth at 1060 nm is 2.38 kHz. The relaxation oscillation frequency is right on 94 kHz.
关键词： single frequency,double-circulator interferometer,saturable absorber,wavelength tunable
更新于2025-11-28 14:24:03
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High-Resolution Temperature Sensor Based on Single-Frequency Ring Fiber Laser via Optical Heterodyne Spectroscopy Technology
摘要： We demonstrate a high-resolution temperature sensor based on optical heterodyne spectroscopy technology by virtue of the narrow linewidth characteristic of a single-frequency fiber laser. When the single-frequency ring fiber laser has a Lorentzian-linewidth <1 kHz and the temperature sensor operates in the range of 3?85 ?C, an average sensitivity of 14.74 pm/?C is obtained by an optical spectrum analyzer. Furthermore, a resolution as high as ~5 × 10?3 ?C is demonstrated through optical heterodyne spectroscopy technology by an electrical spectrum analyzer in the range of 18.26–18.71 ?C with the figure of merit up to 3.1 × 105 in the experiment.
关键词： fiber optics sensors,high resolution,heterodyne spectroscopy,single-frequency laser
更新于2025-11-28 14:24:03
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An optical angle sensor based on chromatic dispersion with a mode-locked laser source
摘要： This paper proposes a new optical angle sensor, in which a mode-locked laser is employed as the light source, and chromatic dispersion of a collimator objective is utilized to detect the angular displacement of a target of interest. In the proposed method, each of the optical modes in the femtosecond laser beam reflected from the reflector mounted on a target of interest is separated from the others by chromatic dispersion of a collimator objective to generate a group of focused laser beams that can be utilized as the scale for measurement of an angular displacement of the target. By detecting the change in peak frequency in optical spectra obtained by the photodetector, a small angular displacement can be measured. In this paper, as the first step of research, a prototype optical setup is developed, and some basic experiments are carried out to demonstrate the feasibility of the proposed method for measurement of angular displacement.
关键词： Chromatic dispersion,Angular displacement,Angle measurement,Optical frequency comb,Laser autocollimation
更新于2025-11-28 14:24:03
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Single-frequency fibre laser at 1030?nm based on gain bandwidth compression
摘要： We demonstrate a single-frequency linear cavity fiber laser at 1030 nm with a distributed Bragg reflector cavity configuration. Despite the fact that the combination of the cavity length of the fiber laser and the reflection band of the output FBG cannot satisfy the condition of single-longitudinal mode oscillation, the single-frequency lasing is still realized by the proper temperature control of two FBGs to narrow the gain bandwidth. Under the respective temperature of two FBGs of 43.4 °C and 9 °C, the laser linewidth of around 9.6 kHz is achieved at a pump power of 113 mW. The relative noise intensity for frequencies of above 1.5 MHz is about ?140 dB Hz?1. The maximum output power of 126.2 mW is obtained with the slope efficiency of about 28%.
关键词： fibre laser,single-frequency,gain bandwidth compression,distributed Bragg reflector
更新于2025-11-28 14:23:57
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Demonstration of linewidth measurement based on phase noise analysis for a single frequency fiber laser in the 2 <i>μ</i> m band
摘要： Linewidth measurement based on phase noise analysis using a 3 × 3 coupler has been applied in the 1550 nm band. One of the obvious advantages of this method compared with the common delayed self-heterodyne method is the low loss caused by the short delay line used. Taking full advantage of this particular characteristic, the linewidth of the single frequency (SF) fiber laser in the 2 μm band can also be measured. However, a specifically experimental demonstration of this method in the 2 μm band is absent to date. In this paper, a high-performance SF thulium-doped fiber laser (TDFL) was proposed and employed for the demonstration. The TDFL operates at the center wavelength of 1942.03 nm with high stability. By means of the phase noise analysis-based linewidth measurement system with a fiber delay line of only 50 m, the linewidth of the proposed TDFL is successfully measured. When the measuring time is 0.001 s, the linewidth is ~47 kHz. Furthermore, the noise characteristics of the SF laser were simultaneously studied by this method.
关键词： 2 μm band,phase noise,single frequency fiber laser,linewidth measurement
更新于2025-11-28 14:23:57
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Resonant electro-optic frequency comb
摘要： High-speed optical telecommunication is enabled by wavelength-division multiplexing, whereby hundreds of individually stabilized lasers encode information within a single-mode optical fibre. Higher bandwidths require higher total optical power, but the power sent into the fibre is limited by optical nonlinearities within the fibre, and energy consumption by the light sources starts to become a substantial cost factor. Optical frequency combs have been suggested to remedy this problem by generating numerous discrete, equidistant laser lines within a monolithic device; however, at present their stability and coherence allow them to operate only within small parameter ranges. Here we show that a broadband frequency comb realized through the electro-optic effect within a high-quality whispering-gallery-mode resonator can operate at low microwave and optical powers. Unlike the usual third-order Kerr nonlinear optical frequency combs, our combs rely on the second-order nonlinear effect, which is much more efficient. Our result uses a fixed microwave signal that is mixed with an optical-pump signal to generate a coherent frequency comb with a precisely determined carrier separation. The resonant enhancement enables us to work with microwave powers that are three orders of magnitude lower than those in commercially available devices. We emphasize the practical relevance of our results to high rates of data communication. To circumvent the limitations imposed by nonlinear effects in optical communication fibres, one has to solve two problems: to provide a compact and fully integrated, yet high-quality and coherent, frequency comb generator; and to calculate nonlinear signal propagation in real time. We report a solution to the first problem.
关键词： optical telecommunication,electro-optic effect,optical frequency combs,wavelength-division multiplexing,whispering-gallery-mode resonator
更新于2025-11-28 14:23:57
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Robust 1.7-μm, all-polarization-maintaining femtosecond fiber laser source based on standard telecom fibers
摘要： We demonstrate a compact 1.7-μm all-polarization-maintaining (PM) ultrafast fiber laser source, which employs soliton self-frequency shift (SSFS) in an optical fiber as the dominant spectral-shifting mechanism. The laser generates stable pulses with 384 fs pulse width and 102 MHz repetition rate centered at 1.7 μm with 7 nm spectral bandwidth. The average power is about 35 mW with a high conversion efficiency of 66 %. The measured root mean square (RMS) output power stability over 10 hours is as low as 0.22 %. Both experimental and simulation results demonstrate that this laser has a potential to improving multiphoton imaging depth.
关键词： all-polarization-maintaining,multiphoton imaging,femtosecond fiber laser,soliton self-frequency shift,1.7-μm
更新于2025-11-28 14:23:57
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Absolute distance measurement based on spectral interferometry using femtosecond optical frequency comb
摘要： We demonstrated an absolute distance measurement method based on the frequency folding e?ect using the spectral interferometry of femtosecond optical frequency comb. And the investigation was carried out on the ranging accuracy in?uence of the phase noise in the traditional complicated phase unwrapping method via band-pass ?lter and Fourier Transform. To reduce the e?ects of the phase noise, we proposed the non-?ltered and di?erential envelop phase demodulation method, and its robustness was illustrated with a standard deviation of 75 nm for the stability of single point measurements. Further, through the extension of the non-ambiguity range, we achieved a resolution of better than 30 ??m in a long distance measurements range of 70 m, yielding a relative precision of 3.1 × 10 ? 7.
关键词： Spectral interferometry,Optical frequency comb,Absolute distance measurement
更新于2025-11-28 14:23:57
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[IEEE 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Va?ster?s (2018.9.3-2018.9.6)] 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Train Communication System with Distributed Antenna System using Optical Frequency Doubler in 90 GHz Band
摘要： A MilliMeter Wave (MMW) backhaul technology for advanced high-speed trains running a tunnel for a long distance is under development for the communication gathering a large number of passenger communications transmitting to the ground. The authors are studying a system that realizes large capacity communication between trains and the ground by arranging Distributed Antenna System (DAS) along with a long distance railway. In order to transmit a radio signal between distant antennas and the main frame of base station physically, it is necessary to avoid the influence of fiber dispersion for Radio over Fiber (RoF) which transmits a radio signal over the light. We are investigating RoF system with optical multiplication which can obtain doubled frequency after transmission. In this paper, we develop the vector modulation signal transmission by the RoF used for the downlink of the base station and report on the result of the packet communication experiment with the base station and the terminal.
关键词： DAS,RoF,millimeter wave,Frequency multiplication
更新于2025-11-28 14:23:57
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Opto-thermally Excited Fabry-Perot Resonance Frequency Behaviors of Clamped Circular Graphene Membrane
摘要： An opto-thermally excited optical fiber Fabry-Perot (F-P) resonant probe with suspended clamped circular graphene diaphragm is presented in this paper. Then, the dependence of resonance frequency behaviors of graphene diaphragm upon opto-mechanical factors including membrane properties, laser excitation parameters and film boundary conditions are investigated via COMSOL Multiphysics simulation. The results show that the radius and thickness of membrane will linearly affect the optical fiber light-induced temperature distribution, thus resulting in rapidly decreasing resonance frequency changes with the radius-to-thickness ratio. Moreover, the prestress can be regulated in the range of 108 Pa to 109 Pa by altering the environmental temperature with a scale factor of 14.2 MPa/K. It is important to note that the availability of F-P resonant probe with a defective clamped circular graphene membrane can be improved notably by fabricating the defected circular membrane to a double-end clamped beam, which gives a broader perspective to characterize the resonance performance of opto-thermally excited F-P resonators.
关键词： opto-thermal actuation,graphene membrane,Fabry-Perot resonator,resonance frequency simulation
更新于2025-11-28 14:23:57