- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Fiber Laser || Passive Q-switched and Mode-locked Fiber Lasers Using Carbon-based Saturable Absorbers
摘要： This chapter aims to familiarize readers with general knowledge of passive Q-switched and mode-locked fiber lasers. It emphasizes on carbon-based saturable absorbers, namely graphene and carbon nanotubes (CNTs); their unique electronic band structures and optical characteristics. The methods of incorporating these carbon-based saturable absorbers into fiber laser cavity will also be discussed. Lastly, several examples of experiments where carbon-based saturable absorbers were used in generating passive Q-switched and mode-locked fiber lasers are demonstrated.
关键词： passive Q-switch,graphene,carbon nanotube,Fiber laser,passive mode-lock
更新于2025-09-16 10:30:52
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[Laser Institute of America ICALEO? 2016: 35th International Congress on Applications of Lasers & Electro-Optics - San Diego, California, USA (October 16–20, 2016)] International Congress on Applications of Lasers & Electro-Optics - Velocity and range measurement optical frequency stepped chirp modulated coherent LIDAR for space application
摘要： The spacecraft landing on Mars or other planets generally requires measuring relative velocity and distance between itself and the land. The measurement demands high accuracy and high reliability. This paper presents an optical frequency stepped chirp modulated pulse train coherent lidar technology for range and velocity measurement. This paper advances an all-fiber structure lidar. It has advantages of small size, high efficiency, low power consumption and stable performance. This paper introduces the optical frequency stepped chirp modulation technology. It gives the semiconductor seed laser theoretical model of driver current versus laser frequency, and computes the modulation waveform. We use an AWG (arbitrary waveform generator) to load the waveform and get the optical stepped chirp modulated pulse train. This paper derives the ambiguous function of the lidar. This function provides a powerful tool to analyze the property and find the highlight property of this lidar: high effective time-bandwidth products. The property gives high range accuracy and velocity accuracy. The signal processing method is advanced. The algorithm can get the range and velocity simultaneously. The Doppler effect caused by target motion is analyzed. The rang walk error caused by Doppler effect is compensated by special algorithm.
关键词： Optical coherence,detection,frequency modulation,lidar,Doppler effect,fiber laser
更新于2025-09-16 10:30:52
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Intra-cavity multi-point sensor for C2H2 detection in photoacoustic spectroscopy based on acousto-optic Q-switched fiber laser
摘要： In this paper, we reported a new multi-point sensor for C2H2 detection based on photoacoustic spectroscopy and acousto-optic Q-switched fiber laser. Three transmission-type PAS cells were placed inside the fiber laser cavity and used for C2H2 detection simultaneously to demonstrate the potential of spatially resolved measurements. A maximum pulse peak power of ~544 mW was generated by the acousto-optic Q-switched fiber laser. The signal-to-noise ratios (SNR) calculated from the experimental results was 57.7 dB, 45.1 dB and 57.2 dB. This resulted in a minimum detection limit (MDL) for C2H2 of 1.73 ppmv, 7.82 ppmv and 1.93 ppmv for PAS cell 1, PAS cell 2 and PAS cell 3, respectively.
关键词： multi-point sensor,photoacoustic spectroscopy,fiber laser
更新于2025-09-16 10:30:52
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Tunable passively Q-switched ultranarrow linewidth erbium-doped fiber laser
摘要： A tunable passively Q-switched erbium-doped fiber laser with ultranarrow linewidth is proposed and demonstrated. With the single wall carbon nanotubes (SWCNTs) as the passive Q-switch, the ultranarrow linewidth laser operation is realized based on spectral filtering effect using an ultranarrow tunable bandpass filter (UNTBF). The Q-switched laser spectrum is tunable from 1525 to 1561 nm, covering a wavelength range of 36 nm. At 1545 nm, the highest repetition rate of ~ 38 kHz and the lowest pulse width of 1.15 μs are obtained, with the corresponding pulse energy of approximately 0.18 nJ. The linewidth measurement using self-heterodyne technique yields a linewidth value of 17.5 kHz, which may be the narrowest linewidth for a Q-switched fiber laser to the best of our knowledge.
关键词： Ultra-narrow linewidth,passively Q-switched,tunable wavelength,erbium-doped fiber laser
更新于2025-09-16 10:30:52
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Wideband saturable absorption in Metal-organic frameworks (MOFs) for mode-locking Er- and Tm-doped fiber laser
摘要： We fabricate a Metal-organic frameworks (MOFs) Saturable absorber (SA) based on a microfiber. Nonlinear optical absorption of the MOF SA is characterized systmatically. The modulation depth is measured to be 6.57 % and 14.25 % at 1.5 and 2 μm spectral ranges, respectively. We report ultrashort pulse generation in both Er- and Tm-doped fiber lasers by using a same microfiber-based MOF SA, operating 384 fs and 1.3 ps pulse duration at 1563 nm and 1882 nm, respectively. To the best of our knowledge, this is the first report on a MOF based fiber laser at near infrared spectral ranges. Our findings validate the applicability of MOF as a broadband SA for ultrafast photonic applications.
关键词： Ultrafast photonics,Saturable absorber,Metal-organic frameworks,Fiber laser,Nonlinear optical absorption
更新于2025-09-16 10:30:52
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A Study of the Optical Properties of a Multimode Silica Optical Fiber with a Reflective Shell from a Fluorinated Thermoplastic Polymer
摘要： The optical properties of a silica–polymer optical fiber with a light-guide core with a diameter of 430 μ m and a reflecting shell with a thickness of 70 μ m from a thermoplastic copolymer of tetrafluoroethylene with ethylene of Tefzel brand have been experimentally studied. The polymer coating is applied to a silica fiber directly in the fiber draw apparatus by the die method from a thermoplastic melt. The optical losses of the drawn fiber and the numerical aperture and its dependence on the fiber length are measured. It is established that a light propagating through the fiber is noticeably scattered by the reflecting shell, which is associated with the crystallinity of the polymer. The distribution of the scattered radiation intensity along the fiber axis and the indicatrix of radiation scattering by the shell are measured. The relative contributions of scattering and absorption of light in the shell to the total optical losses of the fiber are estimated. The possible use of optical fibers of this structure in laser medicine is considered.
关键词： silica–polymer optical fiber,laser medicine,scattering indicatrix
更新于2025-09-16 10:30:52
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Development of all-fiber Fabry-Perot pulse laser with a fiber type saturable absorber and improvement of the oscillation characteristics
摘要： The authors developed high-concentration erbium doped fiber as a saturable absorber, making use of its concentration quenching. Then, they developed an all-fiber Fabry-Perot pulse laser with high-concentration erbium doped fiber and demonstrated that it enables stable and passive pulse oscillation regardless of disturbance. Furthermore, they successfully improve power efficiency and shortening pulse width to 1.8 μs by optimizing the structure of the fiber laser.
关键词： Er doped fiber,fiber laser,concentration quenching,all-fiber passive Q-switching,fiber-type saturable absorber
更新于2025-09-12 10:27:22
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Optical Amplifiers - A Few Different Dimensions || Raman Fiber Laser–Based Amplification in Telecommunications
摘要： The chapter demonstrates a detailed study of Raman fiber laser (RFL)-based amplification techniques and their applications in long-haul/unrepeatered coherent transmission systems. RFL-based amplification techniques are investigated from signal/noise power distributions, relative intensity noise (RIN), and fiber laser mode structures. RFL-based amplification techniques can be divided into two categories according to the fiber laser generation mechanism: cavity Raman fiber laser with two fiber Bragg gratings (FBGs) and random distributed feedback (DFB) Raman fiber laser using one FBG. In addition, in cavity fiber laser–based amplification, reducing the reflectivity near the input helps mitigate the signal RIN, thanks to the reduced efficiency of the Stokes shift from the second-order pump. To evaluate the transmission performance, different RFL-based amplifiers were optimized in long-haul coherent transmission systems. Cavity fiber laser–based amplifier introduces >4.15 dB Q factor penalty, because the signal RIN is transferred from the second-order pump. However, random DFB fiber laser–based amplifier prevents the RIN transfer and therefore enables bidirectional second-order pumping, which gives the longest transmission distance up to 7915 km. In addition, using random DFB laser-based amplification achieves the distance of >350 km single mode fiber in unrepeatered DP-QPSK transmission.
关键词： Raman fiber laser,Raman amplification,coherent transmission,cavity fiber laser,random fiber laser
更新于2025-09-12 10:27:22
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Tm <sup>3+</sup> -Doped Harmonic Dissipative Soliton Mode-Locked Fiber Laser at 1.93 $\mu$ m Based on Tungsten Disulfide in Anomalous Dispersion Regime
摘要： We report a harmonic dissipative soliton 1.93 μm thulium fiber laser based on a tungsten disulfide (WS2) saturable absorber (SA) in the anomalous dispersion regime. The multilayer WS2 nanosheets were prepared by liquid phase exfoliation method and the SA was fabricated by dropping WS2 solution onto a gold mirror. The transferred WS2 SA had a modulation depth of 2.5% and a saturation intensity of 0.82 MW/cm2. By incorporating the SA into a linear Tm3+ fiber laser cavity, harmonic mode-locked dissipative soliton laser was achieved at 1930 nm with the spectral width of 8 nm, the pulse energy of 3 nJ, the pulse width of 3.6 ns, and the repetition rate of 56.3 MHz. Based on the experimental results, it is shown that with the presence of harmonic mode-locking in 2 μm wavelength region, the multilayer WS2 serving as a SA was verified to be a good candidate for broadband high-energy mode-locking. The order of the harmonic dissipative soliton mode-locked pulses remains the same along with the increasing pump power.
关键词： 2 μm fiber laser,2D material,tungsten disulfide,Mode-locked fiber laser,Tm3+-doped fiber
更新于2025-09-12 10:27:22
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Optically Adjustable Random Laser With Multi-phase Shifted Bragg Grating in Er/Yb Co-doped Fiber
摘要： An optically controllable Er/Yb co-doped random fiber laser with a random multi-phase shifted fiber Bragg grating pumped by a 980 nm laser is proposed. We used a 980 nm laser diode to laterally pump an Er/Yb co-doped fiber with a random multi-phase shifted fiber Bragg grating. Through changing lateral pump location, control of laser outputs was achieved. As a result, outputs of one or two main laser peaks were obtained by changing the locations of the Er/Yb co-doped fiber being laterally pumped.
关键词： random fiber grating,Er/Yb co-doped fiber,random fiber laser
更新于2025-09-12 10:27:22