- 标题
- 摘要
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- 实验方案
- 产品
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Development of infrared fiber lasers at 1555?nm and at 2800?nm based on Er-doped zinc-tellurite glass fiber
摘要： We manufactured and characterized a low-loss gain fiber based on high-purity TeO2–ZnO–La2O3–Na2O undoped glass for 100-μm cladding and TeO2–ZnO–La2O3–Na2O glass for 10-μm core doped with 0.24 mol% Er2O3. To confirm that the produced fiber is a promising active element for the infrared range, we demonstrated experimentally broadband laser amplification and CW generation at the 4I13/2 → 4I15/2 transition at 1555 nm with a single-mode diode pump at 975 nm at the 4I15/2 → 4I11/2 transition. We developed a numerical model calibrated to the experimental data for prediction and optimization of laser characteristics in schemes with different parameters. The model describes single- wavelength lasing as well as dual-wavelength cascade lasing at 1555 nm and 2800 nm. It was shown numerically that for the optimized parameters, the maximum slope efficiency at 2800 nm at the 4I11/2 → 4I13/2 transition can reach ~20%. The maximum calculated efficiency at 1555 nm exceeds 30%.
关键词： Numerical model,Infrared fiber lasers,Broadband laser amplification,CW generation,Er-doped zinc-tellurite glass fiber
更新于2025-09-19 17:13:59
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Narrow bandwidth optimization using a polymer microring resonator in a thulium holmium fiber laser cavity
摘要： A thulium–holmium fiber (THDF) laser cavity has been demonstrated with a SU-8 polymer microring resonator (PMRR) in the cavity. The PMRR has a 500 μm radius and fabricated using the lithography method, with the SU-8 polymer acting as a host material. The butt coupling method was used for the horizontal coupling of light from a ultra-high numerical aperture (UHNA) fiber to the polymer waveguide. Lasing in the cavity without the PMRR is obtained at a center wavelength of 1.910 μm, 1.869 μm when the PMMR is inserted into the cavity. A maximum power of -5 dBm was extracted from the laser oscillator, and the laser linewidth was measured to be ～26.6 kHz by radio-frequency spectrum analyzer analysis. The PMRR was able to generate an output with a free spectral range of 0.79 μm at a frequency of 59.25 GHz.
关键词： Thulium–holmium fiber lasers,Narrow bandwidth,Polymer microring resonator
更新于2025-09-19 17:13:59
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Up to 70 THz bandwidth from an implanted Ge photoconductive antenna excited by a femtosecond Er:fibre laser
摘要： Phase-stable electromagnetic pulses in the THz frequency range offer several unique capabilities in time-resolved spectroscopy. However, the diversity of their application is limited by the covered spectral bandwidth. In particular, the upper frequency limit of photoconductive emitters - the most widespread technique in THz spectroscopy – reaches only up to 7 THz in the regular transmission mode due to absorption by infrared-active optical phonons. Here, we present ultrabroadband (extending up to 70 THz) THz emission from an Au-implanted Ge emitter that is compatible with mode-locked ?bre lasers operating at wavelengths of 1.1 and 1.55 μm with pulse repetition rates of 10 and 20 MHz, respectively. This result opens up the possibility for the development of compact THz photonic devices operating up to multi-THz frequencies that are compatible with Si CMOS technology.
关键词： photoconductive antenna,Si CMOS technology,THz emission,Ge emitter,femtosecond fiber lasers
更新于2025-09-19 17:13:59
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2.4 GHz L-Band Passively Harmonic Mode Locked Er-Doped Fiber Laser Based on Carbon Nanotubes Film
摘要： We experimentally demonstrate a passively harmonic mode locked (PHML) Er-doped fiber laser with pump power efficiency up to 17 MHz/mW operating at L-band based on single walled carbon nanotubes polyvinyl alcohol (SWCNTs-PVA) film. Under 233 mW pump power, the stable pulse train at 1594.97 nm with 40.5 dB side mode suppression ratio (SMSR) and 742 fs pulse duration is obtained at a repetition rate of 1.923 GHz, corresponding to 170th harmonic of the fundamental frequency. Under optimized intracavity conditions, the pulses frequency is able to scale up to 2.415 GHz with a high level of 40 dB SMSR, which to the best of our knowledge, is the highest value yet reported from a L-band PHML fiber laser incorporating SWCNTs as saturable absorber (SA). Such high repetition rate and stable fiber laser operating at L band may be desirable for various applications.
关键词： nanomaterials.,Mode locked fiber lasers,mode locking
更新于2025-09-19 17:13:59
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Milliwatt-Level Spontaneous Emission Across the 3.5a??8 ?μm Spectral Region from Pr3+ Doped Selenide Chalcogenide Fiber Pumped with a Laser Diode
摘要： A spontaneous emission fiber source operating in the mid-infrared (MIR) wavelength range from 3.5 to 8 μm is demonstrated for the first time at output power levels of at least 1 mW. The source is a Pr3+-doped selenide chalcogenide, multimode, glass fiber pumped with commercially available laser diodes operating at 1.470 μm, 1.511 μm and 1.690 μm. This MIR spontaneous emission fiber source offers a viable alternative to broadband mid-infrared supercontinuum fiber sources, which are comparatively complex and costly. The MIR emission wavelength range is significant for molecular sensing applications across biology and chemistry, and in medicine, agriculture, defense, and environmental monitoring.
关键词： mid-infrared,mid-infrared light sources,fiber lasers,chalcogenide glass fibers
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Bismuth and Bismuth Telluride Thin Films Deposited by MOCVD upon Tapered Fiber Sections as Q-switches for Fiber Lasers
摘要： Lasing regimes of ring erbium ?ber lasers passively Q-switched by means of ?ber tapers coated with thin crystalline ?lms of either Bi2Te3 or Bi as saturable absorbers (SAs) are investigated. 10–15 μm in diameter and 5–10 mm long ?ber tapers are prepared by local chemical etching out of a silica light re?ecting cladding of the standard SMF-28 optical ?ber. Nanometer thick island ?lms of pure Bi and Bi2Te3 are synthesized on the surface of the ?ber tapers by applying the metalorganic chemical vapor deposition (MOCVD). The deposited ?lms are then covered with two di?erent polymers: either polyvinyl acetate (PVA) or polydimethylsiloxane elastomer (PDMSE). The ?ber section with polymer-coated SA ?ber is installed into the ring laser cavity in tandem with the section of an active ?ber. For all the samples a stable generation of microsecond pulses in the Q-switch mode at a wavelength of about 1560 nm is observed. To the best of our knowledge, a passively Q-switched ?ber laser with nanometer Bi ?lms as a saturable absorber is implemented for the ?rst time. It is established that even a small increase in the temperature of the surrounding medium leads to a signi?cant increase in the transmission coe?cient of polymer-coated tapers with deposited SA ?lms, which may be attributed to a decrease in the refractive index of the polymers. The most signi?cant increase in the transmission coe?cient with increasing temperature is observed in tapers coated with PVA, which has a refractive index larger than fused silica.
关键词： MOCVD,Q-switches,polymer coating,saturable absorbers,Bi2Te3,fiber lasers,Bi
更新于2025-09-19 17:13:59
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Graded‐Index Ytterbium‐Doped Optical Fiber Fabricated through Vapor Phase Chelate Delivery Technique
摘要： Herein, the fabrication of ytterbium-doped graded refractive-index few-mode fiber (GRIN-FMF) is described for the first time following a vapor phase chelate delivery technique. Investigation is carried out to find out the best possible approach to fabricate the preform. The optimization of the process steps along with composition and associated process parameters leads to a parabolic refractive-index profile with a profile parameter of 2 in the developed fiber. A large core of 30 μm diameter and a low numerical aperture (NA) of 0.08 with graded distribution of dopant ions is achieved with a good repeatability. Amplification gain of more than 20 dB with good beam quality for pulses with kW peak power without any distortion in temporal, spectral, and spatial profile proves the potential of the fiber for many promising applications.
关键词： preform fabrication,graded-index fibers,ytterbium,vapor phase chelate delivery,fiber lasers
更新于2025-09-19 17:13:59
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ZnS Nanospheres for Optical Modulator in an Erbiuma??Doped Fiber Laser
摘要： Zinc sulfide (ZnS), which belongs to transition metal monochalcogenides, is a semiconductor material with wide direct band gap. It can potentially show some special applications (such as luminescence, phosphor, sensors, infrared window materials, photocatalysis) by changing the morphology, size, and crystal structure of semiconductor materials. However, ZnS nanospheres have not been studied as optical modulators until now. Herein, ZnS nanospheres are synthesized by the hydrothermal method and are used to realize optical modulators in an Er-doped fiber laser. The evanescent field effect is utilized to incorporate the ZnS nanospheres on a tapered fiber. Furthermore, with the increase in pump power, the modulation interval gradually decreases to a minimum of 34.36 ns corresponding to the modulation frequency of 29.1 MHz, which is the highest modulation frequency to our knowledge in a ring cavity all-fiber laser. These results demonstrate ZnS nanospheres together with the interaction of dispersion and nonlinearity in optical fibers can modulate the proposed lasers. This not only provides a new method for controlling the power and frequency of all optical modulators, but also marks an important step for ZnS materials in optics research and device applications.
关键词： optical modulators,nonlinear optical materials,ring cavity fiber lasers
更新于2025-09-19 17:13:59
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Numerical Investigation of the Impact of the Saturable Absorber Recovery Time on the Mode-locking Performance of Fiber Lasers
摘要： We investigated the impact of the recovery time of a saturable absorber (SA) on the mode-locking performance of a fiber laser. This study was conducted for two types of fiber cavities with different net cavity group velocity dispersion (GVD) at a wavelength of 1.55 μm: normal and anomalous. The impact of modulation depth variation was also analyzed. It was found that the recovery time of the SA has little influence on the output pulse characteristics in the case of the anomalous net cavity GVD due to an interplay between saturable absorption-induced pulse shaping and modulation instability-induced soliton evolution, irrespective of the SA operating in the fast or slow saturable absorption regime. However, the recovery time was found to have a significant impact on the output pulse characteristics for the case of a normal net cavity GVD. An SA operating in the fast saturable absorption regime produces mode-locked pulses with symmetric temporal shapes for the normal GVD cavity, whereas asymmetric pulses are generated in the slow saturable absorption regime. From the simulation results, the optimum recovery time range for fiber laser mode-locking is discussed.
关键词： Fiber lasers,cavity dispersion,mode-locking,saturable absorber
更新于2025-09-19 17:13:59
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A novel repetition rate adjustable SBS-based Q-switched fiber laser
摘要： We experimentally demonstrated a novel repetition rate adjustable SBS-based Q-switched fiber laser. An inserted Fabry-Perot interferometer formed by two non-contact end faces of two FC/PC fiber connectors was inserted to help the system stabilize the random output of SBS-based Q-switching. By mechanically fine-tuning the length of the inserted Fabry-Perot interferometer, a linear and continuous repetition rate adjustment under a fixed pump power was achieved. This method paves a new way for the indirect control of repetition rate in SBS-based Q-switched fiber lasers. It is also found out that higher pump power allows wider adjustment range. At 600 mW pumping which is highest pump power of the source, the repetition rate almost tripled from 11.22 kHz to 32.06 kHz only by varying the length of FP cavity in less than 3 μm. In the meantime, the variation of pulse width, output power and single pulse energy were recorded and analyzed under different fixed pump powers. Although the adjusting range of repetition rate is not very wide but the tuning of repetition rate due to such a small length changing is unique and valuable. This original repetition rate control technique has great potential in areas like environment sensing and material detections.
关键词： tunable lasers,fiber lasers,Q-switched lasers
更新于2025-09-16 10:30:52