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oe1(光电查) - 科学论文

14 条数据
?? 中文(中国)
  • Ultrafast mode-locked dual-wavelength thulium-doped fiber laser using a Mach-Zehnder interferometric filter

    摘要: A simple and robust method to generate a dual-wavelength mode-locked laser using a tunable Mach-Zehnder filter (TMZF) and a single-wall carbon nanotube (SWCNT) based saturable absorber (SA) is proposed and demonstrated. The proposed laser uses a thulium-doped fiber for lasing in the two-micron region and exploits the interferometric spectrum of the TMZF to produce dual peaks with nearly equal magnitude. SWCNT based SA enables mode-locking at a threshold value of 150.4 mW with distinct dual-wavelength peaks at 1919.2 nm and 1963.7 nm. The peaks have a calculated pulse width of 1.8 ps and 1.6 ps, respectively with a repetition rate of 9.1 MHz with a relatively high optical-signal-to-noise ratio value of 59.1 dB. The output is also observed to remain unchanged over time, indicating high stability. The proposed laser has a promising application, particularly in ultrafast gas molecular spectroscopy and sensing.

    关键词: Thulium-doped fiber laser,Mode-locking,Dual-wavelength,Mach-Zehnder filter

    更新于2025-11-28 14:24:03

  • Pure gold saturable absorber for generating Q-switching pulses at 2?μm in Thulium-doped fiber laser cavity

    摘要: We experimentally demonstrate Q-switched Thulium-doped fiber laser operating at 1949.19 nm using pure gold saturable absorber (Au-SA) as a Q-switcher. The Au-SA was fabricated by depositing gold particles molecules using electron beam evaporation on the surface of a polyvinyl alcohol (PVA) film. Subsequently, stable Q-switched pulses were obtained within the 1552 nm pump power range from 343.1 to 467.3 mW, with repetition rate tuned from 11.7 kHz to 21.95 kHz. At 467.3 mW pump power, the TDFL produced pulses train with the pulse width of 2.6 μs and the maximum pulse energy of 89.8 nJ. These results propose that pure gold could be a promising saturable absorber for pulse generation in 2 μm wavelength region.

    关键词: Thulium-doped fiber laser,Q-switching,Pure gold saturable absorber

    更新于2025-11-28 14:24:03

  • Self-wavelength-sweeping in a bi-directional thulium-doped fiber ring laser

    摘要: We report for the first time the self-wavelength-sweeping phenomenon of a bi-directional thulium-doped fiber ring laser. The laser wavelength can spontaneously sweep in both lasing directions at a rate up to 0.2 nm s?1 over 15 nm sweeping range in the 1.95 μm wavelength region. The sweeping rate can be controlled by simply changing the state of polarization of the laser cavity. The laser can be tuned to generate a periodical wavelength-swept output with microsecond pulses in the time domain. The sweep rate can also be tuned to zero to give a static lasing wavelength.

    关键词: self-wavelength-sweeping,thulium-doped fiber ring laser,polarization control,bi-directional

    更新于2025-11-28 14:23:57

  • Comparison of A 1940 nm Thulium-Doped Fiber Laser and A 1470 nm Diode Laser for Cutting Efficacy and Hemostasis in A Pig Model of Spleen Surgery

    摘要: Partial and total splenectomies are associated with a high risk of substantial blood loss. Lasers operating at wavelengths strongly absorbed by water have the potential to improve hemostasis and cut while providing a narrow zone of thermal damage. The aim of this study is to compare a thulium-doped fiber laser (TDFL) emitting a wavelength of 1940 nm and a diode laser (DL) operating at 1470 nm for spleen surgery in a pig model. A partial splenectomy and spleen incisions were made in 12 animals using the two laser devices. The hemostasis was evaluated visually during surgeries. Post-mortem and histopathological evaluations were done on days 0, 7, and 14 following surgery. Neither TDFL nor DL caused bleeding on day 0 or delayed bleeding. On day 14, pale streaks at the site of incision were slightly wider after cutting with DL than with TDFL. Histological analysis revealed a carbonized zone with exudation and a deeper zone of thermal tissue damage on day 0. The width of the thermal changes was 655.26 ± 107.70 μm for TDFL and 1413.37 ± 111.85 μm for DL. On day 7, a proliferation of fibroblasts and splenocytes was visible, as well as a formation of multinucleated giant cells adjacent to the residues of carbonization. The zone of thermal damage was broader for DL (1157.5 ± 262.77 μm) than for TDFL (682.22 ± 116.58 μm). On day 14, cutting sites were filled with connective and granulation tissues with the residues of carbonization. The zone of thermal damage was narrower for TDFL (761.65 ± 34.3 μm) than for DL (1609.82 ± 202.22 μm). Thus, both lasers are efficient in spleen surgery, providing good hemostasis. However, TDFL produces a narrower zone of thermal damage, which suggests its better efficiency for spleen surgery, especially when performing more precise procedures.

    关键词: thulium-doped fiber laser (1940 nm),pig model of spleen surgery,diode laser (1470 nm),thermal damage zone,partial splenectomy,hemostasis

    更新于2025-09-19 17:13:59

  • Stable Multi-wavelength Thulium-doped All-fiber Laser Incorporating a Multi-cavity Fabry-Perot Filter

    摘要: The present manuscript experimentally demonstrates multi-wavelength generation from a thulium-doped all-fiber laser by implementing a multi-cavity Fabry-Perot filter. The filter, with a composition that relies of several silica-air and air-silica interfaces, provide a spectral reflection response that allows the laser to be operated in single-, dual- or triple-wavelength emissions by simple and clear adjustment of the polarization state. In this way, the fiber laser is capable to operate over a broad range of wavelengths extending from 1844 to 1928 nm. In addition, dual-wavelength operations are also feasible in the 1844 and 1928 nm regions, exhibiting a mode spacing of 4.41 nm and 1.62 nm, respectively. Beside this, the laser is able to switch to a sextuple-wavelength operation regime in the 1885 nm region, maintaining a minimum wavelength spacing of 1.53 nm. The laser demonstrates high wavelength stability, with variations below 60 pm at all analyzed wavelengths, and a minimum peak power fluctuation of ±2.77 dB.

    关键词: Fiber Laser,Fabry-Perot Filter,Thulium-doped Fiber,Multi-wavelength

    更新于2025-09-16 10:30:52

  • Wavelength-tunable thulium-doped fiber laser with sampled fiber Bragg gratings

    摘要: A continuous wave (CW) wavelength-tunable Tm3+-doped fiber laser with two sampled fiber Bragg gratings (SFBGs) has been proposed and demonstrated. This proposed laser is stable operating with a significant 14.44 nm wavelength range from 1942.09 nm to 1956.53 nm due to the Vernier effect. The laser OSNRs of different wavelengths ranged from 45 dB to 58 dB at a launched pump power of 3.67 W. The wavelength shift and power fluctuation were less than 0.03 nm and 0.46 dB, respectively. An 8.62% slope efficiency was achieved using a grating for laser extracting. To the authors’ knowledge, this is the first time that a wavelength-tunable Tm3+-doped fiber laser with two SFBGs has been demonstrated.

    关键词: Wavelength-tunable,Thulium-doped fiber laser,Sampled fiber Bragg grating

    更新于2025-09-16 10:30:52

  • Mode-locking and self-mode-locking-like operation in a resonantly pumped gain-switched Tm-doped fiber laser

    摘要: Mode-locking and mode-locking-like operation in a fast gain-switched Tm-doped fiber laser have been investigated experimentally. Applying a SESAM mirror, stable gain-switched and regular mode-locked pulses at a wavelength of ~2μm are reported. The repetition rates of the gain-switched pulses and mode-locked sub-pulses are 50 kHz and 111 MHz, respectively. The duration of sub-pulses recorded within one gain-switched pulse envelope is ~110 ps. Besides, in the same laser system configuration, it has been found that self-starting mode-locked resembling pulses, attributed to mode beating, can be generated. To the best of our knowledge, it is the first report on a gain-switched fiber laser where both modes of operation have been demonstrated.

    关键词: Fiber laser,Mode-locking,Thulium-doped fiber,Gain-switching

    更新于2025-09-16 10:30:52

  • Generation of Two Dissipative Soliton Resonance Pulses in an All-Anomalous-Dispersion Regime Thulium-Doped Fiber Laser

    摘要: In this paper, we demonstrate experimentally a thulium-doped passively mode-locked figure-of-eight fiber laser to generate dissipative-soliton-resonance (DSR) pulses in an all-anomalous-dispersion regime. And two different DSR pulses are obtained by simply adjusting the polarization controllers. At maximum pump power of 2.4 W, the average power and repetition rate of two DSR pulses is 113.5 mW and 2.532 MHz respectively, corresponding to a pulse energy of 45 nJ. Subsequently, the effect of NALM length on the two DSR pulses is investigated, and pulses with maximum pulse energy of 63 nJ near 2 μm are obtained.

    关键词: dissipative soliton resonance,Thulium-doped fiber laser

    更新于2025-09-16 10:30:52

  • [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) - Improvement of soliton pulse energy in thulium-doped fiber laser

    摘要: In this paper, we report a thulium-doped fiber laser based on non-polarization rotation technique. Increasing the pump power to 2500 mW and adjusting the polarization controllers, Baussian pulse with high pulse energy can be achieved. The pulse duration of de-chirped pulse is 242 fs. Due to dispersion management, most related studies are still focused on the 1 μm band, and few reports are available for the 2 μm band. By using non-polarization rotation technique, the mode-locked start-up threshold can be avoided. At the maximum pump power, the direct output power of the resonator cavity is 272.2 mW, and the corresponding single pulse energy is 1.825 nJ.

    关键词: mode-locking,thulium-doped fiber laser,non-polarization rotation technique,dispersion management

    更新于2025-09-16 10:30:52

  • Switchable multiwavelength thulium-doped fiber laser with cylindrical vector beam emission

    摘要: We experimentally demonstrate a switchable multiwavelength thulium-doped fiber laser with cylindrical vector beam (CVB) emission, which is the first report, to our best knowledge, on the generation of CVBs in a 2 μm wavelength band. The Sagnac loop filter, made up of a 50:50 coupler, a section of polarization-maintaining fiber and a polarization controller, serves as a periodical filter and accounts for the excitation of multiwavelength channels. The mode-selective coupler consisting of both tapered single-mode and four-mode fibers has been designed and fabricated as a mode converter from LP01 to LP11 mode with a purity of >80%. By adjusting the polarization controllers, laser outputs with 1–3 switchable wavelengths have been realized in the spectrum ranging from 1988–1998 nm. The laser could find miscellaneous applications in wavelength/mode-division multiplexing system, etc.

    关键词: cylindrical vector beams (CVBs),thulium-doped fiber laser (TDFL),multiwavelength fiber laser,mode conversion

    更新于2025-09-12 10:27:22