- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[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) - Tunable Near 3-μm Difference Frequency Generation using Ytterbium and Broadband Seed Erbium Fiber Lasers
摘要： The absorption peaks corresponding to vibrational energy levels of various molecules are located in the mid-infrared (mid-IR) spectral range. For instance, the interatomic bonding of hydrogen and another heavier element (e.g. C-H, O-H, N-H) that is a part of some organic and inorganic molecules is characterized by the absorption peak located near 3μm wavelength. Laser sources operating at this wavelength can be useful tools for medical applications, non-metallic materials processing, and spectroscopy [1]. The study of the interaction of various organic substances with mid-IR radiation is rather challenging because of their great diversity and chemical composition complexity. An application of the laser source with high output power and tunable wavelength can significantly facilitate possible investigation problems [2,3]. This research is devoted to the elaboration of the tunable laser source of mid-IR radiation using single pass difference frequency generation of the pump (1.03 μm) and seed (1.55 μm) radiation in periodically poled lithium niobate (PPLN) crystal (see Fig.1 (a)). Pulsed ytterbium and erbium fiber lasers were used as the pump and seed radiation sources respectively. Both of them were assembled basing on a MOPA optical scheme, pulse duration was about 2 ns and repetition rate was 3 MHz. The average output power of Yb-laser was up to 50 W, which is five times higher than the maximum power of Er laser source. The wavelength corresponding to the difference frequency generation for these fiber lasers lies in the 3 μm region. The spectrum of the seed radiation was considerably broadened in the delivery fiber due to the four-wave mixing and Raman scattering. So that, it was possible to obtain the seed radiation in the spectral range from 1.55 m to 1.60 μm. The selective parametric amplification region of seed radiation can be shifted by changing PPLN temperature, as a result, the idler radiation wavelength tuning was achieved. We obtained the idler tuning in 2.9–3.1 μm wavelength range by changing the PPLN temperature from 45 °C to 110 °C. This tuning range was restricted by the spectral width of the Er-laser radiation. The idler radiation power varied from 5.5 W to 8.0 W in the whole tuning range (see Fig.1 (b)). The conversion efficiency reached 15% in respect to the Yb-laser power. As we were not able to measure directly the mid-IR radiation spectrum but it was derived using the experimentally measured spectrum of the amplified seed radiation. Normalized calculation results are shown in Fig.1 (c). The spectral width of the output mid-IR radiation reached 20-30 nm (at a 3 dB FWHM level).
关键词： tunable laser source,mid-infrared,difference frequency generation,PPLN crystal,erbium fiber laser,ytterbium fiber laser
更新于2025-09-11 14:15:04
-
Noise-Like Pulse Generation Using Polarization Maintaining Mode-Locked Thulium-Doped Fiber Laser With Nonlinear Amplifying Loop Mirror
摘要： We investigate noise-like pulse (NLP) generation in a mode-locked thulium-doped fiber laser with nonlinear amplifying loop mirror (NALM) and different net anomalous dispersions. The all-polarization maintaining (PM) fiber oscillator generates pulse trains with a frequency adjustable in the range of 4.06–20.4 MHz by utilizing different lengths of PM passive fiber in the NALM loop. An NLP with a coherence spike width of 232 fs was generated at 1993.6 nm with a 3-dB spectral width of 32.6 nm when the net cavity dispersion was ?0.711 ps2.
关键词： thulium-doped fiber,mode-locked laser,NALM,fiber laser,noise-like generation
更新于2025-09-11 14:15:04
-
Gain-switched Dy3+:ZBLAN fiber laser operating around 3 μm
摘要： A gain-switched Dy3+-doped ZBLAN fiber laser operating at 2.943 μm is experimentally reported for the first time to the best of our knowledge. The laser was pumped by a 1.1 μm Q-switched ytterbium (III) fiber laser constructed in-house. A stable pulse train is achieved with repetition rates spanning between 25 and 100 kHz. For the repetition rate of 50 kHz, stable 183 ns pulses with an energy of 0.72 μJ and peak power of 4 W are recorded. By using a longer length of Dy3+-doped ZBLAN fiber, gain-switched operation was achieved at a wavelength larger than 3 μm.
关键词： Mid infrared sources,Mid infrared fiber laser,Dysprosium doped glass,pulse fiber laser
更新于2025-09-11 14:15:04
-
Manufacture and spectroscopic analysis of Tm<sup>3+</sup>-doped silica glass and microstructure optical fiber through the laser sintering technique
摘要： We demonstrated Tm3+-doped silica glass rod was successfully manufactured by laser sintering technique and it was made into Tm3+-doped microstructure optical fiber by stack-capillary-draw method. Based on the absorption spectrum, the core glass shows outstanding spectroscopic properties through Judd-Ofelt analysis. Fiber core-cladding structure was preserved completely without any crystallization in the core. Besides, a self-built fiber laser at 1.95 μm produces 740 mW output power with a slope efficiency of 16.73 %. The results prove that our laser sintering technique is a promising preparation method to acquire fiber materials for 2.0 μm laser.
关键词： microstructure optical fiber,fiber laser,Judd-Ofelt analysis,laser sintering technique,Tm3+-doped silica glass
更新于2025-09-11 14:15:04
-
Switchable multi-wavelength thulium-doped fiber laser employing a polarization-maintaining sampled fiber Bragg grating
摘要： A continuous wave, switchable multi-wavelength, thulium-doped fiber laser (TDFL) with a polarization-maintaining sampled fiber Bragg grating (PM-SFBG) is proposed and demonstrated for the first time. A length of 150 m highly-nonlinear fiber (HNLF) was used to introduce the four-wave mixing effect for the efficient suppression of the wavelength competition existing in the gain medium of thulium-doped fiber. By adjusting the state of polarization (SOP) of light in the laser cavity, two six-wavelength operations at two orthogonal SOPs and a ten-wavelength operation were obtained. When the TDFL ran at the six-wavelength operation mode with a pump power of 4.11 W, there were at least four lasing wavelengths with an optical signal-to-noise ratio (OSNR) higher than 30 dB, and when it ran at the ten-wavelength operation mode with a pump power of 4.60 W, there were nine lasing wavelengths with an OSNR higher than 30 dB. Regardless of the operation mode, the TDFL exhibited high stability.
关键词： sampled fiber Bragg grating,thulium-doped fiber laser,multi-wavelength
更新于2025-09-11 14:15:04
-
[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) - Dual-Wavelength Dual-Comb Mode Locked Er-Doped Fiber Laser Based on Saganc Fiber Loop Mirror
摘要： We report an all-fiber dual-wavelength dual-comb mode locked fiber laser based on a Sagnac fiber loop mirror. Two asynchronous mode locked pulse trains with repetition rate difference of 218 Hz was realized.
关键词： fiber laser,Sagnac fiber loop mirror,mode locked,dual-wavelength,dual-comb
更新于2025-09-11 14:15:04
-
Tunable single-longitudinal-mode fiber laser based on a chirped fiber Bragg grating
摘要： In this paper, a tunable single-longitudinal-mode (SLM) fiber laser based on a chirped fiber Bragg grating (CFBG) is proposed and experimentally demonstrated. Multi-sub-cavities formed by a single CFBG inserted inside the laser loop greatly increase the longitudinal mode spacing so that SLM operation can be obtained. The SLM laser output can be tuned in a wide wavelength range from 1535 to 1565 nm by simply adjusting the central wavelength of a tunable optical band-pass filter (TOBF). A side-mode suppression ratio of larger than 50 dB and a linewidth of less than 8.5 kHz have been respectively achieved.
关键词： Single-longitudinal-mode (SLM),Fiber laser,Chirped fiber Bragg grating (CFBG)
更新于2025-09-11 14:15:04
-
Switchable multi-wavelength fiber laser based on hybrid structure optical fiber filter
摘要： A switchable multi-wavelength fiber laser based on a novel hybrid structure optical fiber filter (HSOFF) is proposed and demonstrated. The HSOFF is consisted of single mode fiber (SMF)-few mode fiber (FMF) with two ellipsoidal structures and FMF-SMF with a core-offset splicing point. Two ellipsoidal structures can effectively excite the high-order modes, then the high-order modes interfere with fundamental mode at the core-offset splicing point. It can be demonstrated that the HSOFF has the comb filter property with the maximum extinction ratio is more than 13 dB while the insert loss is only 9.95 dB. Using HSOFF in proposed laser system, a switchable multi-wavelength fiber laser with stable dual-, triple- and quadruple wavelength lasers can be obtained by adjusting the state of polarization controller, at the same time the lasing wavelength locations also can be switched. The optical signal to noise ratio (OSNR) is larger than 30.68 dB, and this laser exhibits the excellent stability at room temperature.
关键词： Mode interference,Ellipsoidal structure optical fiber,Core-offset,Multi-wavelength fiber laser
更新于2025-09-11 14:15:04
-
[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) - Self-Sweeping Operation of Nd-Doped Fiber Laser
摘要： The self-induced laser frequency sweeping (“self-sweeping” for short) effect in fiber lasers was observed in 2011 [1]. In this case the lasers generate self-sustained pulses and its frequency drifts slowly from pulse to pulse in one direction and jumps back after reaching a border of sweeping region. The self-sweeping operation is based on formation of long-lived dynamical phase and gain gratings. The gratings are connected to modulation of population inversion inside the active medium induced by the field of a standing wave formed in a linear cavity [2]. Dynamical gratings inscribed in the cavity by previously generated longitudinal modes are kept in the active medium for a relatively long time as compared with lifetime of a single mode and affects generation of the next spectral components. Due to broad sweeping range (more than 10 nm) and simplicity, self-sweeping fiber lasers are attractive sources for applications demanding tunable radiation. As a result, the self-sweeping laser is the simplest sort of tunable laser without any tuning elements and electrical drivers for frequency tuning. Currently the self-sweeping operation was observed in almost all common fibers: ytterbium [1-2], bismuth [3], erbium [4], holmium [5] and thulium [6]. It should be noted that the self-sweeping operation has been demonstrated up to now only in quasi-three-level laser systems. In the present paper, we demonstrate for the first time self-sweeping operation in a four-level laser system based on neodymium. The Nd-doped fiber with length of 3 meter is pumped by multi-mode laser diode with wavelength of 805 nm. The cavity is formed by highly-reflective fiber loop mirror and right-angle cleaved fiber end. Two fiber Lyot filters and a 10 nm bandpass filter were used for restriction of sweeping region. The self-induced spectral dynamics is observed in the region of 1.06 μm with range of up to 1.8 nm (Fig.1a). The laser generates periodic pulses (Fig.1b) where each of them contains single longitudinal mode radiation, which is confirmed by heterodyning with single-frequency probe radiation. The laser frequency is changed from pulse to pulse by one intermode beating frequency of the laser ~7.5 MHz. The sweeping rate is increased with pump power up to 10 nm/sec. The output power exceeds 600 mW. Self-sweeping operation for Nd-doped fiber in the new spectral range of 0.93 μm instead of standard 1.06 μm is expected.
关键词： four-level laser system,tunable radiation,fiber laser,Nd-doped,self-sweeping
更新于2025-09-11 14:15:04
-
Effect of optical fiber diameter and laser emission mode (cw vs pulse) on tissue damage profile using 1.94?μm Tm:fiber lasers in a porcine kidney model
摘要： Purpose To evaluate the ablation capacity using two Thulium fiber lasers (TFL) in a porcine kidney model. Methods All tissue samples were mounted on a motorized stage for a precise speed of cutting. A continuous wave (cw) TFL and a super pulsed (SP) TFL were used at power settings of 60 and 120?W with 200 and 600?μm laser fibers. After lactate dehydrogenase staining, histological evaluation was performed to measure the vaporization volume (VV), ablation depth (AD), thermo-mechanical damage zones (TMZ), coagulation zones (CZ) and the carbonization grade (CG). Results At 120?W, no significant differences were seen between 200 and 600?μm fibers utilizing the cw TFL regarding VV (24.6 vs. 28.2?mm3/s), AD (5.6 vs. 5.7?mm), TMZ (0 vs. 0?mm2) and CZ (18.1 vs. 12.3?mm2). Using the SP TFL, no significant differences between both fiber diameters with regard to VV (4 vs. 6.2?mm3/s), AD (2.7 vs. 3.4?mm), TMZ (1 vs. 2.6?mm2) and CZ (3.1 vs. 2.2?mm2) at 120?W were found, respectively. However, the VV of the cw TFL at 60?W was significantly less compared to 120?W using 200 and 600?μm fibers, respectively, whereas the SP TFL did not show significant differences between 60 and 120?W with regard to VV. SP TFL showed a consistently lower CG compared to cw TFL. Conclusions This experiment suggests that there is no significant difference using 200 or 600?μm laser fibers in cw or SP TFLs. However, the cw TFL produces a coagulation zone three to five times larger than the SP TFL regardless of the fiber diameter.
关键词： Porcine kidney,In-vitro,Thulium fiber laser,Laser
更新于2025-09-11 14:15:04