- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Analysis of laser radiation using the Nonlinear Fourier transform
摘要： Modern high-power lasers exhibit a rich diversity of nonlinear dynamics, often featuring nontrivial co-existence of linear dispersive waves and coherent structures. While the classical Fourier method adequately describes extended dispersive waves, the analysis of time-localised and/or non-stationary signals call for more nuanced approaches. Yet, mathematical methods that can be used for simultaneous characterisation of localized and extended fields are not yet well developed. Here, we demonstrate how the Nonlinear Fourier transform (NFT) based on the Zakharov-Shabat spectral problem can be applied as a signal processing tool for representation and analysis of coherent structures embedded into dispersive radiation. We use full-field, real-time experimental measurements of mode-locked pulses to compute the nonlinear pulse spectra. For the classification of lasing regimes, we present the concept of eigenvalue probability distributions. We present two field normalisation approaches, and show the NFT can yield an effective model of the laser radiation under appropriate signal normalisation conditions.
关键词： eigenvalue probability distributions,signal normalisation,Zakharov-Shabat spectral problem,mode-locked pulses,Nonlinear Fourier transform
更新于2025-09-12 10:27:22
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Oxidation-resistance Black Phosphorus Enable Highly Ambient-stable Ultrafast Pulse Generation at 2 μm Tm/Ho-doped Fiber Laser
摘要： Black phosphorus (BP) ranks among the most promising saturable absorber materials for ultrafast pulse generations at 2 μm. However, the easy-to-degrade characteristic of BP seriously limits the long-term operation of ultrafast fiber lasers and hence becomes a bottleneck for its relevant practical applications. In this paper, a modified electrochemical delamination exfoliation process was explored to produce high-performance, large-size and oxidation-resistance BP nanosheets, where BP nanosheets in high yield with evenly coated tetra-n-butyl-ammonium (TBA) organics by precisely controlling the intercalation chemistry can be obtained. A mode-locked Tm/Ho co-doped fiber laser with high temporal stability and long-term operation capability was demonstrated based on the innovatively-fabricated BP saturable absorber. The self-starting mode-locking operation featuring high signal-to-noise ratio of 58 dB and long-term stability has been verified for at least three weeks, which indicates the successful passivation of the employed synthesis method. These results fully indicated that passivated BP is an efficient candidate in 2 μm range ultrafast photonics field, which will promote the ultrafast optical application of BP and also other infrared photonic and photoelectronic devices.
关键词： mode-locked laser,2D materials,fiber laser,mid-infrared,black phosphorus
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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Harmonic Mode-Locking in Bidirectional Domain-Wall Soliton Fiber Lasers
摘要： We report on the first experimental observation of passively harmonic mode-locking (HML) in a bidirectional domain-wall dark-soliton fiber laser. The domain-wall solitons (DWSs) are characterized, in which, the strong coupling between the two directions takes great responsibility for the generation. By appropriately altering the polarization state in the cavity, the stable fundamental domain-wall solitons and HML states could be obtained and switched with increasing the pump power. In our experiment, the repetition rate can be tunable from the fundamental mode locking of 2.96 MHz up to eighth-order HML of 23.68 MHz when the pump power is increased from 120 to 542.5 mW. Importantly, this HML operation of dark-pulse DWSs confirms that the DWSs are the intrinsic feature of the mode-locked lasers, as well as the conventional bright solitons. This work could provide a new perspective to the understanding of the formation and transformation of dark solitons, which may also find great potential applications in fiber sensing and future optical communication systems.
关键词： lasers and laser optics,mode-locked lasers,ultrafast photonics,pulse propagation and temporal solitons
更新于2025-09-12 10:27:22
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Generation of high-energy and low-repetition rate hybrid pulses from a passively mode-locked Tm-Ho co-doped laser
摘要： This study presents a passively mode-locked Tm-Ho co-doped ?ber laser at around 1840 nm with a low-repetition rate and high pulse energy. The laser delivers pulses at 93 kHz and produces a pulse energy of 18.5 nJ at 0.55 W pump power when the cavity length is 2.21 km. When the pump power is increased, high order of repetition rate outputs are observed. By a comparison of the spectra at various pump power levels indicates that the laser can be operated at hybrid multi-wavelength soliton mode-locking, depending on the pumping intensity. With the increase in pump power, single-wavelength soliton mode-locking and simultaneous of single- and dual-wavelength soliton mode locking are also observed. Besides, the system produces a laser at 1417 nm, which is induced by two-step absorption and the consequent stimulated emission. The low–repetition rate and high–pulse energy ?ber laser at around 1840 nm has potential applications in sensing, processing, and surgery research.
关键词： Optical ?ber lasers,Mode locked lasers,Ultrafast optics
更新于2025-09-12 10:27:22
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High-Power Large-Energy Raman Soliton Generations Within a Mode-Locked Yb-Doped Fiber Laser Based on High-Damage-Threshold CVD-MoS2 as Modulator
摘要： In our work, based on a high-damage-threshold MoS2 saturable absorber (SA), high-power intra-cavity Raman solitons within a passively mode-locked Yb-doped fiber laser were demonstrated successfully for the first time. The damage threshold of the MoS2 SA was as high as ~0.48 J/cm2. By adjusting the polarization states, stable single- or dual-pulse Raman soliton operations were obtained. The maximum average output power for single-pulse and dual-pulse Raman soliton operations was 80.11 and 89.33 mW, respectively. Our experiment results show significant enhancement in comparison with previous works, which provides fundamental guidance for future designs of high-power, large-energy, intra-cavity Raman soliton generations based on two-dimensional materials as SAs.
关键词： mode-locked Raman fiber laser,high-damage 2D MoS2 materials,ultra-fast optical modulation
更新于2025-09-12 10:27:22
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Internal nonlinear transmission in an Yb mode-locked fiber laser through bifurcations
摘要： Mode-locked fiber lasers are rich dynamical systems that may present several different types of pulsed operating modes, depending on external control parameters such as pump power. A systematic experimental characterization of such regimes is a challenging problem. Here single pulse regimes of ytterbium mode-locked fiber laser are explored and related to the nonlinear amplitude modulation affecting the pulses inside the laser cavity. To understand the full dynamics of this system, average power measurements (slow time scale) have been performed and compared to simultaneous time-resolved measurements (fast time scale). The average nonlinear transmission resulting from the amplitude modulation is measured, allowing to relate the transitions between dynamical regimes to the system’s nonlinearity.
关键词： Mode-locked fiber laser,Transmission curve,Nonlinear dynamics
更新于2025-09-12 10:27:22
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Mechanism of formation of noiselike pulses in passively mode-locked fiber lasers
摘要： We present the results of an analysis of noiselike pulses generated in passively mode-locked ?ber lasers with anomalous dispersion. The master equation used for the analysis takes into account the gain saturation, the quadratic frequency dispersion of the gain and the refractive index, and the cubic-quintic nonlinearity of the losses and refractive index. Reasons for the stabilization of noiselike pulses are investigated. It is found that the space-time localization of a noiselike pulse is associated with the suppression of single solitons located outside this pulse. The mechanism of such competition between single solitons and a noiselike pulse is determined.
关键词： noiselike pulses,passively mode-locked ?ber lasers,solitons,anomalous dispersion,nonlinear optics
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Wide and Continuous Tunable Mode-Locked Erbium-Doped Fiber Laser Based on the Graphene Oxide
摘要： In addition to the artificial saturable absorber (SA) like the nonlinear polarization rotation (NPR), the investigation of peculiar soliton dynamics from passive mode-locked fiber laser (PML-FL) can be produced based on the semiconductor saturable absorber mirror (SESAM) and various nanomaterials, like the carbon nanotube (CNT), graphene, graphene oxide (GO), topological insulator (Bi2Se3) with lower mode-locked threshold. In comparison with other SAs, GO reveals various advantages including relative widely operation bandwidth, easy fabrication, low saturation intensity, ultrashort recovery time. For specific application, the wavelength tuning of PML-FL is required but is limited for the SESAM or CN. Recently, the wavelength tuning of mode-locked Er-doped fiber laser (EDFL) around 1570-1600 nm has been demonstrated based on graphene because of its relative wide absorption range. In this work, we demonstrated the fine tuning of emission peak wavelength of EDFL based on the GO/PVA film.
关键词： Erbium-doped fiber laser,mode-locked,graphene oxide,wavelength tuning
更新于2025-09-12 10:27:22
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170 mW-level mode-locked Er-doped fiber laser oscillator based on nonlinear polarization rotation
摘要： In our work, by optimizing the length of the cavity and using high-power home-made pump source, based on the commonly-used nonlinear polarization rotation (NPR) technique, we designed a stable all-fiber high-power Er-doped mode-locked laser successfully. The maximum average output power was as high as 174 mW under the pump power of 2659 mW. To our knowledge, 174 mW was a new record average output power of NPR based all-fiber mode-locked Er-doped fiber laser, which was much higher than the results reported previously. Our work will provide a significant reference for future demonstrations of high-power mode-locked Er-doped fiber lasers and promote the applications of mode-locked Er-doped oscillators.
关键词： Er-doped fiber laser,mode-locked,high-power,nonlinear polarization rotation
更新于2025-09-12 10:27:22