- 标题
- 摘要
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- 实验方案
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Nanotube mode-locked, wavelength and pulsewidth tunable thulium fiber laser
摘要： Mode-locked oscillators with highly tunable output characteristics are desirable for a range of applications. Here, with a custom-made tunable filter, we demonstrate a carbon nanotube (CNT) mode-locked thulium fiber laser with widely tunable wavelength, spectral bandwidth, and pulse duration. The demonstrated laser’s wavelength tuning range reached 300 nm (from 1733 nm to 2033 nm), which is the widest-ever that was reported for rare-earth ion doped fiber oscillators in the near-infrared. At each wavelength, the pulse duration can be regulated by changing the filter’s bandwidth. For example, at ~1902 nm, the pulse duration can be adjusted from 0.9 ps to 6.4 ps (the corresponding output spectral bandwidth from 4.3 nm to 0.6 nm). Furthermore, we experimentally and numerically study the spectral evolution of the mode-locked laser in presence of a tunable filter, a topic that has not been thoroughly investigated for thulium-doped fiber lasers. The detailed dynamical change of the mode-locked spectra is presented and we observed gradual suppression of the Kelly sidebands as the filter’s bandwidth is reduced. Further, using the polarization-maintaiing (PM) cavity ensures that the laser is stable and the output laser’s polarization extinction ratio is measured to exceed 20 dB.
关键词： thulium fiber laser,spectral bandwidth,polarization-maintaiing cavity,Kelly sidebands,tunable wavelength,pulse duration,Mode-locked oscillators,carbon nanotube
更新于2025-11-28 14:23:57
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Nonlinear Optics || Ultrafast and Intense-Field Nonlinear Optics
摘要： There is currently great interest in the physics of ultrashort laser pulses. Recent advances have led to the generation of laser pulses with durations of the order of 1 attosecond (Hentschel et al., 2001). Ultrashort pulses can be used to probe the properties of matter on extremely short time scales. Within the context of nonlinear optics, ultrashort laser pulses are of interest for at least two separate reasons. The ?rst reason is that the nature of nonlinear optical interactions is often profoundly modi?ed through the use of ultrashort laser pulses, in part because of the broad spectral bandwidth necessarily associated with such pulses. The next two sections of this chapter treat various aspects of the resulting modi?cations of the nature of nonlinear optical interactions. The second reason is that ultrashort laser pulses tend to possess extremely high peak intensities (because laser pulse energies tend to be established by the energy-storage capabilities of laser gain media), and thus short laser pulses tend to have much higher peak powers than longer pulses. The second half of this chapter is devoted to a survey of the sorts of nonlinear optical processes that can be excited by extremely intense laser ?elds.
关键词： attosecond pulses,ultrashort laser pulses,high peak intensities,spectral bandwidth,nonlinear optics
更新于2025-09-23 15:21:01
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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) - Sign-Alternating Dispersion Patterning for Supercontinuum Generation
摘要： Supercontinuum generation (SCG), a process that generates a wide and coherent bandwidth of light, has become foundational in emergent optical technologies in a plethora of fields, such as optical coherence tomography (OCT), metrology (e.g., integrated photonic Kerr combs) and precision sensing. As advanced applications of SCG emerge, the requirements on the spectral bandwidth, the coherence, its temporal compressibility, and the quality of the optical spectral content (e.g., a uniformly flat spectral profile) are increasing. Moreover, as these technologies need not be restricted to the lab, the spectral conversion efficiency of SCG must increase from current technology that functions, e.g., in the tens of nJ pulse energy, to sub nJ levels.
关键词： precision sensing,optical coherence tomography,spectral bandwidth,coherence,metrology,Supercontinuum generation,spectral conversion efficiency,temporal compressibility
更新于2025-09-16 10:30:52
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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) - Monolithic Master Oscillator with Tapered Power Amplifier Diode Laser at 1060 nm with Additional Control Section for High Power Operation
摘要： State of the art diode laser light sources for high power operation with good beam quality are distributed Bragg reflector tapered diode lasers (DBR-TPLs). These devices deliver over 10 W of spectrally narrowband emission within an almost diffraction-limited beam [1]. However, due to the integration of the tapered section into the resonator, these devices are designed that only a forward traveling wave is optimal confined and amplified. This trade-off limits the potential of these devices. One way to overcome this limitation is to move the tapered section outside of the resonator and use as a single pass power amplifier in a monolithic master oscillator power amplifier (MOPA) layout [2]–[4]. However, the benefits on the emissions characteristics, as discussed below, of these devices can diminish if multi-cavity operation occurs. In this work, we present results on recently developed monolithic MOPAs for enhanced suppression of multi-cavity operation. The MOs in these devices are 2 mm long with a 7th order DBR grating at the front- and backside and a 0.75 mm long active section in the middle. An active 0.5 mm long control section (CON) follows the MO section. Both have a ridge waveguide (RW) width of 5 μm. The PA section is 3.5 mm long and defined by the tapered p-side contact with a full angle of 6°. The 3 different layouts are depicted in Fig. 1 a). In the first layout (top) all three section are in a straight line perpendicular to the front facet. The second layout (middle) has a MO section tilted by 4° and a bent CON section and the third layout (bottom) has bent CON section and a PA section tilted by 4°. Fig. 1 a) Sketch of all three monolithic MOPA layouts. b) Optical output power (solid lines) and the peak wavelength (dots) for three different monolithic MOPAs. The straight layout is used as reference to discuss the benefits of a bent control section and either a tilted MO or tilted PA on the emission characteristics of the devices. Furthermore the influence of the control section on the emission characteristics of the devices will be presented. This includes a comparison of the optical output power, the spectra and the beam quality factor of the devices. All devices provide over 6 W of optical output power at 1060 nm within a narrow spectral bandwidth below 17 pm (spectrometer resolution limit). However the overall emission characteristics have clear differences as can be seen in Fig. 1 b). Here the optical output power and the peak wavelength are plotted in dependence of the PA current. The laser with the tilted MO layout shows a small increase in output power compared to the straight layout and a reduction of spectral mode jumps for PA currents below IPA = 8 A. For the laser with the tilted PA layout the small spectral mode jumps due to multi-cavity operation are completely suppressed but the output power is reduced by 0.5 W.
关键词： MOPA,spectral bandwidth,diode laser,monolithic master oscillator power amplifier,high power operation,beam quality
更新于2025-09-11 14:15:04