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- 摘要
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- 实验方案
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2a??10???μm Mida??Infrared Fibera??Based Supercontinuum Laser Source: Experiment and Simulation
摘要： Mid-infrared supercontinuum (mid-IR SC) sources in the 2–20 μm molecular fingerprint region are in high demand for a wide range of applications including optical coherence tomography, remote sensing, molecular spectroscopy, and hyperspectral imaging. Herein, mid-IR SC generation is investigated in a cascaded silica-ZBLAN-chalcogenide fiber system directly pumped with a commercially available pulsed fiber laser operating in the telecommunications window at 1.55 μm. This fiber-based system is shown to generate a flat broadband mid-IR SC covering the entire range from 2 to 10 μm with several tens of mW of output power. This technique paves the way for low cost, practical, and robust broadband SC sources in the mid-IR without the requirement of mid-infrared pump sources or Thulium-doped fiber amplifiers. A fully realistic numerical model used to simulate the nonlinear pulse propagation through the cascaded fiber system is also described and the numerical results are used to discuss the physical processes underlying the spectral broadening in the cascaded system. Finally, recommendations are provided for optimizing the current cascaded system based on the simulation results.
关键词： soft-glass fibers,nonlinear optics and solitons,supercontinuum generation,chalcogenide fibers,fiber lasers,ZBLAN fibers
更新于2025-09-23 15:21:01
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Saturable plasmonic metasurfaces for laser mode locking
摘要： Metamaterials are artificial materials made of subwavelength elementary cells that give rise to unexpected wave properties that do not exist naturally. However, these properties are generally achieved due to 3D patterning, which is hardly feasible at short wavelengths in the visible and near-infrared regions targeted by most photonic applications. To overcome this limitation, metasurfaces, which are the 2D counterparts of metamaterials, have emerged as promising platforms that are compatible with planar nanotechnologies and thus mass production, which platforms the properties of a metamaterial into a 2D sheet. In the linear regime, wavefront manipulation for lensing, holography, and polarization control has been achieved recently. Interest in metasurfaces operating in the nonlinear regime has also increased due to the ability of metasurfaces to efficiently convert incident light into harmonic frequencies with unusual polarization properties. However, to date, the nonlinear absorption of metasurfaces has been mostly ignored. Here, we demonstrate that plasmonic metasurfaces behave as saturable absorbers with modulation performances superior to the modulation performance of other 2D materials and exhibit unusual polarimetric nonlinear transfer functions. We quantify the link between saturable absorption, the plasmonic resonances of the unit cell and their distribution in a 2D metasurface, and finally provide a practical implementation by integrating the metasurfaces into a fiber laser cavity operating in pulsed regimes driven by the metasurface properties. As such, this work provides new perspectives on ultrathin nonlinear saturable absorbers for applications where tunable nonlinear transfer functions are needed, such as in ultrafast lasers or neuromorphic circuits.
关键词： fiber lasers,metamaterials,plasmonic,saturable absorbers,metasurfaces,nonlinear optics
更新于2025-09-23 15:21:01
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All-fiber short-pulse vortex laser with adjustable pulse width
摘要： A laser with short pulse width and direct output of a vortex beam was reported herein. This laser was fabricated from a nonlinear loop mirror (NOLM) and a coupler composed of a single mode fiber and few-mode fiber fused together. The NOLM is responsible for generating pulses, and the coupler acts as a beam splitter and mode converter. Two stable vortex modes can be formed by adjusting the polarization controller, whose pulse widths are 1.098 ps and 542 fs, respectively.
关键词： optical vortex,fiber lasers,mode-locked laser
更新于2025-09-23 15:21:01
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Broadband Ultrashort Pulses in Passively Mode-Locked Fiber Lasers
摘要： Generation of ultrashort pulses with an ultimately broad spectrum in fiber lasers is investigated by using numerical modeling and analytical calculations. It is demonstrated that the spectral width of the generated pulses can be several times larger than the gain bandwidth of the laser active medium.
关键词： passive mode-locking,spectra of pulses,generation dynamics,fiber lasers
更新于2025-09-23 15:21:01
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Sub-200-kHz single soliton generation in a long ring Er-fiber laser with strict polarization control by using twisted fiber
摘要： In the present work we demonstrate a novel single-soliton ultra-low pulse repetition frequency passively mode-locked erbium-doped fiber laser. We mitigate the residual linear birefringence of fiber by fiber twist to achieve a strict control of polarization. For mode-locking the nonlinear polarization rotation (NPR) was used. Special technique was applied to reduce the overdriving of NPR that allows the generation of single soliton in ultra-long cavity. The strict control of polarization yields a stable relation between the polarization state of the pulses propagating in the cavity and the regimes of generation. A 192.12-kHz train of soliton pulses was obtained with pulse duration of 4.7 ps at 1560.1 nm, the average power was 29 μW and the estimated peak power was ? 30.8 W with an energy of 150.9 pJ.
关键词： Ultra-long laser cavity,Solitons,Nonlinear optics,Overdriving nonlinear effects,Mode-locked fiber lasers
更新于2025-09-23 15:19:57
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Modal instabilities in high power fiber laser oscillators
摘要： Transverse mode competition and instabilities in high-power fiber oscillators have been studied experimentally by monitoring the dynamic power exchanges and characteristic frequencies of the transmitted fundamental mode (FM) and scattered high-order modes (HOMs) of the fiber laser cavity under CW and pulsed pumping. The FM and HOM power evolution indicates the presence of two competing effective laser cavities which result in rich output dynamics and full chaotic operation. The thermal and inversion related contributions to the observed instabilities have been identified by monitoring the associated characteristic instability frequencies under pulsed pumping. It is shown that in the transient regime, both inversion and thermal effects contribute successively to the observed power instabilities. Increasing the pump power leads to full chaotic response through an interplay between transverse and longitudinal mode instabilities.
关键词： Transverse mode instability,inversion effects,thermal effects,high-power fiber lasers,mode competition
更新于2025-09-23 15:19:57
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Temperature sensor based on IR-laser reduced Graphene Oxide
摘要： A simple, cost-effective approach to realize a sensitive temperature sensor based on IR laser reduced graphene oxide (IRLrGO) is reported. The sensor has been obtained by irradiating a graphene oxide (GO) film, placed between two thin glass substrates, with a continuous wave diode laser operating at 970 nm along its entire length. A conductive strip, 13 mm long, 300 μm wide and 7 μm thick, has been generated by moving the GO film on an X-Y translator stage with a given velocity with respect to the fixed laser fiber tip position. The laser treatment has given rise to the GO reduction confirmed by the resistance R measurements as well as from SEM, EDX, ATR-FTIR and Raman analyses. The temperature dependence of the conductive strip resistance has been measured in air from 30?C to 80?C and in high vacuum from 80 K to 300 K. The sample acts as a sensitive and low mass Resistance Temperature Detector (RTD). Such a sensor is biocompatible and requires a very low bias (<1 V). While the performances of the IRLrGO temperature sensor are stable under high vacuum conditions at room temperature, its behavior remains to be studied when it operates under different environmental conditions.
关键词： Interaction of radiation with matter,Materials for solid-state detectors,Fiber Lasers
更新于2025-09-23 15:19:57
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Semiconducting Polymer Dots as Broadband Saturable Absorbers for Q-switched Fiber Lasers
摘要： Semiconducting polymer dots (Pdots) have attracted much attention due to their outstanding optical properties. However, Pdots potential in laser technology is rare. Here, we first report the benzobisthiadiazole (BBT)-based Pdot as a single broadband nonlinear saturable absorber (SA) for passively Q-switched fiber lasers at 1, 1.5, and 2 μm. The Pdots-SA possesses a strong saturable absorption, broadband nonlinear optical response, and large modulation depth. Once the Pdots-SA is integrated into the ytterbium-, erbium-, and thulium-doped fiber laser cavities, stable Q-switched operations are observed at the central wavelengths of 1036, 1561, and 1951 nm. Our results verify that the Pdots are promising nonlinear media for Q-switched pulses generation, and highlight the potential of Pdots for relevant nonlinear optical applications.
关键词： Saturable absorber,Semiconducting polymer dots,Q-switched fiber lasers,Broadband nonlinear optical response
更新于2025-09-23 15:19:57
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Experimental observation of bound states of Q-switched fiber lasers mode-locked by carbon nanotubes
摘要： We demonstrate the experimental observation of bound states of Q-switched lasers mode-locked by carbon nanotubes. When bound states of Q-switched mode-locked lasers are formed, the Fourier transformation results into multiwavelength spectrum due to the small temporal interval induced by polarization controller. We find that the wavelength spacing is highly sensitive to pump power. A wavelength spacing tuning from ~0.057 nm to 1.569 nm with a pump power variation less than 4 mW is obtained. The wavelength spacing is also highly sensitive to the nonlinear phase induced by polarization controller. These findings enrich our understanding about the complex dynamics of the Q-switched mode-locked lasers.
关键词： carbon nanotubes,bound states,mode-locked,nonlinear phase,Q-switched fiber lasers
更新于2025-09-23 15:19:57
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The Analysis of Fiber and CO <sub/>2</sub> Laser Cutting Accuracy
摘要： The aim of the conducted research was to compare the functional properties and the cutting accuracy of items produced using Fiber lasers in comparison with CO2 lasers. The object of 6 mm thick sheet plates made of S235JR steel cut with the two different laser types were analyzed. The tests covered dimensional accuracy (in accordance with the PN EN 22768-fH standard) and the surface after cutting (in accordance with the PN-EN ISO 9013: 2017-04). The results of the analysis have demonstrated that for the same welding linear energy, more accurate cutting surface is obtained using Fiber laser cutting.
关键词： CO2 lasers,Fiber lasers,S235JR steel,surface quality,cutting accuracy,dimensional accuracy
更新于2025-09-19 17:13:59