Academic literature on the topic 'Fiber laser, ytterbium doped fiber laser system, pulsed laser operation, high power laser'

We present ytterbium doped silica single-mode fibre components for high power and high energy laser applications. We developed in-house the fibre laser with high efficiency of 65% according to the launched power, the threshold of 1.16W and the fibre length of 20 m. We also elaborated the fibre with 20 µm in diameter core suitable for amplifying the beam generated in oscillator. We implemented made in-house endcaps to prove the utility of the fibre towards high peak power applications. Full Text: PDF ReferencesStrategies Unlimited, The Worldwide Market for Lasers: Market Review and Forecast, 2020 DirectLink J. Zhu, P. Zhou, Y. Ma, X. Xu, and Z. Liu, "Power scaling analysis of tandem-pumped Yb-doped fiber lasers and amplifiers", Opt. Express 19, 18645 (2011) CrossRef IPG Photonics, Product information, accessed: October, 2020. DirectLink J.W. Dawson, M. J. Messerly, R. J. Beach, M. Y. Shverdin, E. A. Stappaerts, A. K. Sridharan, P. H. Pax, J. E. Heebner, C. W. Siders, and C. P. J. Barty, "Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power", Opt. Express 16, 13240 (2008) CrossRef W. Koechner, "Solid-State Laser Engineering", Springer Series in Optical Science, Berlin 1999 CrossRef A. V. Smith, and B. T. Do, "Bulk and surface laser damage of silica by picosecond and nanosecond pulses at 1064 nm", Appl. Opt. 47, 4812 (2008), CrossRef M. N. Zervas, C. Codemard, "High Power Fiber Lasers: A Review", IEEE J. Sel. Top. Quantum Electron. 20, 1, 2014 CrossRef D.J. Richardson, J. Nilsson, and W.A. Clarkson, "High power fiber lasers: current status and future perspectives [Invited]", J. Opt. Soc. Am. B, 27, 63, 2010, CrossRef M. Li, X. Chen, A. Liu, S. Gray, J. Wang, D. T. Walton; L. A. Zenteno, "Limit of Effective Area for Single-Mode Operation in Step-Index Large Mode Area Laser Fibers", J. Lightw. Technol., 27, 3010, 2009, CrossRef J. Limpert, S. Hofer, A. Liem, H. Zellmer, A. Tunnermann., S. Knoke, and H. Voelckel, "100-W average-power, high-energy nanosecond fiber amplifier", App.Phys.B 75, 477, 2002, CrossRef

An all-fiber thulium-doped fiber laser operating at a wavelength of 1940 nm is reported. A maximum output continuous-wave power of 70.7 W with a slope efficiency of 59%, determined with respect to the absorbed pump power, was demonstrated. The laser delivered almost a single-mode beam with a beam quality factor of < 1.3.Full Text: PDF ReferencesM. N. Zervas and C. A. Codemard, "High Power Fiber Lasers: A Review", IEEE J. Sel. Top. Quantum Electron. 20, 0904123 (2014). CrossRef D. J. Richardson, J. Nilsson, and W. A. Clarkson. "High power fiber lasers: current status and future perspectives [Invited]", J. Opt. Soc. Am. B 27, B63 (2010). CrossRef J. Swiderski, A. Zajac, and M. Skorczakowski, "Pulsed ytterbium-doped large mode area double-clad fiber amplifier in MOFPA configuration", Opto-Electron. Rev. 15, 98 (2007). CrossRef M. Eckerle et al. "High-average-power actively-modelocked Tm3+ fiber lasers", Proc. SPIE 8237, 823740 (2012). CrossRef J. Swiderski, D. Dorosz, M. Skorczakowski, and W. Pichola, "Ytterbium-doped fiber amplifier with tunable repetition rate and pulse duration", Laser Phys. 20, 1738 (2010). CrossRef P. Grzes and J. Swiderski, "Gain-Switched 2-μm Fiber Laser System Providing Kilowatt Peak-Power Mode-Locked Resembling Pulses and Its Application to Supercontinuum Generation in Fluoride Fibers", IEEE Phot. J. 10, 1 (2018). CrossRef S. Liang et al. "Transmission of wireless signals using space division multiplexing in few mode fibers", Opt. Express 26, 6490 (2018). CrossRef J. Swiderski, M. Michalska, and P. Grzes, "Broadband and top-flat mid-infrared supercontinuum generation with 3.52 W time-averaged power in a ZBLAN fiber directly pumped by a 2-µm mode-locked fiber laser and amplifier", Appl. Phys. B 124, 152 (2018). CrossRef F. Zhao et al. "Electromagnetically induced polarization grating", Sci. Rep. 8, 16369 (2018). CrossRef J. Sotor et al. "Ultrafast thulium-doped fiber laser mode locked with black phosphorus", Opt. Lett. 40, 3885 (2015). CrossRef M. Olivier et al. "Femtosecond fiber Mamyshev oscillator at 1550 nm", Opt. Lett. 44, 851 (2019). CrossRef J. Swiderski and M. Michalska, "Over three-octave spanning supercontinuum generated in a fluoride fiber pumped by Er & Er:Yb-doped and Tm-doped fiber amplifiers", Opt. Laser Technol. 52, 75 (2013). CrossRef C.Yao et al. "High-power mid-infrared supercontinuum laser source using fluorotellurite fiber", Optica 5, 1264 (2018). CrossRef J. Swiderski and M. Maciejewska, "Watt-level, all-fiber supercontinuum source based on telecom-grade fiber components", Appl. Phys. B 109, 177 (2012). CrossRef O. Traxer and E. X. Keller, "Thulium fiber laser: the new player for kidney stone treatment? A comparison with Holmium:YAG laser", World J. Urol., 1-12 (2019). CrossRef M. Michalska, et al. "Highly stable, efficient Tm-doped fiber laser—a potential scalpel for low invasive surgery", Laser Phys. Lett. 13, 115101 (2016). CrossRef R. L. Blackmon et al. "Thulium fiber laser ablation of kidney stones using a 50-μm-core silica optical fiber", Opt. Eng., 54, 011004 (2015). CrossRef A. Zajac et al. "Fibre lasers – conditioning constructional and technological", Bull. Pol. Ac.: Tech. 58, 491 (2010). CrossRef C. Guo, D. Shen, J. Long, and F. Wang, "High-power and widely tunable Tm-doped fiber laser at 2 \mu m", Chin. Opt. Lett. 10, 091406 (2012). CrossRef F. Liu et al. "Tandem-pumped, tunable thulium-doped fiber laser in 2.1 μm wavelength region", Opt. Express 27, 8283 (2019). CrossRef H. Ahmad, M. Z. Samion, K. Thambiratnam, and M. Yasin, "Widely Tunable Dual-Wavelength Thulium-doped fiber laser Operating in 1.8-2.0 mm Region", Optik 179, 76 (2019). CrossRef N. M. Fried, "Thulium fiber laser lithotripsy: An in vitro analysis of stone fragmentation using a modulated 110‐watt Thulium fiber laser at 1.94 µm", Lasers Surg. Med. 37, 53 (2005). CrossRef N. M. Fried, "High‐power laser vaporization of the canine prostate using a 110 W Thulium fiber laser at 1.91 μm", Lasers Surg. Med. 36, 52 (2005). CrossRef E. Lippert et al. "Polymers Designed for Laser Applications-Fundamentals and Applications", Proc. SPIE 6397, P639704 (2006). CrossRef N. Dalloz et al. "High power Q-switched Tm3+, Ho3+-codoped 2μm fiber laser and application for direct OPO pumping", Proc. SPIE 10897, 108970J (2019). CrossRef N. J. Ramírez-Martinez, M. Nunez-Velazquez, A. A. Umnikov, and J. K. Sahu, "Highly efficient thulium-doped high-power laser fibers fabricated by MCVD", Opt. Express 27, 196 (2019). CrossRef T. Ehrenreich et al. "1-kW, All-Glass Tm:fiber Laser", Proc. SPIE 7580, 758016 (2010). DirectLink L. Shah et al. "Integrated Tm:fiber MOPA with polarized output and narrow linewidth with 100 W average power", Opt. Express 20, 20558 (2012). CrossRef H. Zhen-Yue, Y. Ping, X. Qi-Rong, L. Qiang, and G. Ma-Li, "227-W output all-fiberized Tm-doped fiber laser at 1908 nm", Chin. Phys. B 23, 104206 (2014). CrossRef

Interest in laser crystallization (LC) of silicon (Si) thin films has been on the rise in fabrication of polycrystalline silicon (pc-Si) based thin/ultrathin photovoltaic solar cells and Si based thin film transistors (TFT). Laser based fabrication of device quality pc-Si thin films at room temperature is expected to be a key enabling technology because of its low energy, material and process time budget. Fabrication of high-quality pc-Si thin films without pre-/post-treatment at large is a disruptive technology which has the potential to revolutionize the Si thin film industry. We hereby describe in detail a multi-wavelength laser processing platform specially developed for crystallization of amorphous silicon (a-Si) thin films into pc-Si thin films. The platform has three main stages. The first stage consists of a nanosecond pulsed ytterbium (Yt3+) doped fibre-laser with a master oscillator power amplifier architecture, operating at a wavelength of 1064 nm with an adjustable repetition rate between 80 kHz–300 kHz. The output beam has a maximum power of 18 W with a pulse energy of 90 µJ. The pulse durations can be set to values between 15 ns–40 ns. The second stage has free-space optical elements for second harmonic generation (SHG) which produces an emission at a wavelength of 532 nm. Conversion efficiency of the SHG is 25% with an output pulse energy of 20 µJ. The platform provides two wavelengths at either 1064 nm or 532 nm in crystallization of a-Si films for different crystallization regimes. The last stage of the platform has a sample processing assembly with a line-focus, which has an x-y motorized stage on a vibration isolated table. Speed of the motorized stage can be set between 1 mm/s–100 mm/s. Stage speed and repetition rate adjustments help to adjust overlap of successive pulses between 97.22–99.99%. Our platform has variety of tune parameters that make it a uniquely flexible system for delicate Si thin film crystallization. A large selection of operational parameter combinations, the wavelength selection and simultaneous x-y scanning capability allow users to crystallize Si films on various substrates optimally. The operation wavelength choice can be done by considering optical absorption and thickness of a-Si films on different types of substrates. Hence, delivering precise amount of absorbed energy in the line-focus irradiation is useful in increasing the average size of crystalline domains; moreover, nucleation of crystallites can be initiated either from the top or bottom interface of the film. Continuous and simultaneous motion of the stage in two dimensions allows to process arbitrary continuous pc-Si geometries in a-Si film. In summary, our multi-wavelength laser processing platform offers all-in-one LC utility for intricate LC-Si processing.

A laser modulation and amplification system is designed to meet the demand of long-range space optical communication, which uses the high-speed semiconductor laser to integrate electro-absorption (EA) modulator as a seed source. Two optical fiber amplifier technologies are used. The erbium-doped fiber amplifier (EDFA) and single-mode semiconductor laser pumping are used in the first-level; erbium ytterbium co-doped fiber amplifier (EYDFA) and 2-4 multimode fiber laser pumping with good temperature characteristics are used in the second level, and the control method is automatic gain control. The experimental result shows that the modulation rate achieves to 10Gbps, and the output optical power achieves to 5W.

The traditional technology in production of doped fiber has disadvantage of low doping concentration, uneven distribution of refractive index, being difficult to produce large core diameter etc. This paper according to the demand of high-power ytterbium doped photonic crystal fiber laser, makes a research of producing methods to large mode area, Yb3+ doped photonic crystal fiber. Anhydrous doping nanometer particles are obtained by solution doping method, using plasma non-chemical vapor deposition method produce fiber core material, large mode area, ytterbium doped fiber sample is made and laser properties experiments has been done. By experiments it is found that at 2cm pre-end of the sample has violet light, Yb3+ doped fiber has laser operation.

In this paper, we summarize the fundamental properties and review the latest developments in high power ytterbium-doped fiber (YDF) lasers. The review is focused primarily on the main fiber laser configurations and the related cladding pumping issues. Special attention is placed on pump combination techniques and the parameters that affect the brightness enhancements observed in high power fiber lasers. The review also includes the major limitations imposed by fiber nonlinearities and other parasitic effects, such as optical damage, modal instabilities and photodarkening. The paper summarizes the power evolution in continuous-wave (CW) and pulsed YDF lasers and their impact on material processing and other industrial applications.

Abstract In this work, we have developed an analytical model of an actively Q-switched Ytterbium-doped fiber laser by using two coupled cavities with amplifying fibers in Mach–Zehnder interferometer configuration. This oscillator system provides high peak power and high energy nanosecond pulse. The pulse energy is almost twice the energy of an individual fiber laser with a combining efficiency goes up 99%. This concept brings some novel perspectives for scaling the high energy and high peak power of nanosecond pulse fiber laser.

Fiber lasers represent the state-of-the-art in laser technology and hold great promise for a wide range of applications because they have a minimum of exposed optical interfaces, very high efficiency, and are capable of exceptional beam quality. In the near future, the most important markets such as micromachining, automotive, biomedical and military applications will begin to use this technology. The scope of this thesis is to design and develop a short picosecond pulsed fiber laser using rare-earth doped fiber as a gain medium. The proposed master oscillator power amplifier (MOPA) will be used to generate pulses with high repetition rates. In this study, first we explain the basic theoretical background of nonlinear optics and fiber laser. Then, the numerical simulation will be introduced to explain how the laser system design and optimization. The simulation is based on nonlinear Schrö
dinger equation with the method of split-step evaluation. The brief theoretical background and simulation results of the laser system will be shown. Finally, the experimental study of the developmental fiber laser system that comprises an oscillator, preamplifier and power amplifier will be discussed.

In recent years laser technology has increasingly developed with the use of fiber lasers and this has provided the possibility to implement different techniques in the defense industry. LADAR is at the forefront of these techniques. Fiber lasers constitute a perfect source for LADAR systems due to their excellent robustness, compact size and high-power generation capability. In this study we will explore the development of a pulsed fiber laser source for a LADAR system that can obtain high resolution 3D images in eye-safe region. A high power, all fiber integrated erbium system with strictly single mode operation in eye-safe region based on MOPA (master oscillator power amplifier) configuration with seed source and amplifier part was developed. Both the use of an actively mode locked laser with erbium doped fiber and fiber coupled modulated distributed feedback diode laser were investigated as seed sources for the amplifier part. Both erbium doped single clad fiber and erbium-ytterbium doped double clad gain fiber were used in this amplifier system. After amplification of the actively mode locked laser, 12 W of average optical power was obtained through single mode fiber with 1ns pulse duration at 10 MHz which corresponds to 1.2 kW peak power. For the fiber coupled DFB diode laser, 9.5W average power was obtained with around 8 ns duration pulses at 100 kHz and about 9.2 W average power was also obtained with around 700 ps duration pulses at 1 MHz through strictly single mode fiber at the output of the same amplifier system as was used in the actively mode locked seed source. In both cases calculated peak power was around 10 kW v which is estimated as the highest peak power for an all fiber integrated system with single mode operation. The development of such a fiber system with high power capability, compact size and free of misalignment is expected to be useful for LADAR application as well as other areas such as eye surgery, 3D silicon processing or any other material processing applications.

碩士
國立清華大學
光電工程研究所
99
雷射在不同的工業中已被廣泛的應用。本論文是研發一種適用於以材料加工的高功率脈衝式光纖雷射。首先，我們設計及架設一台皮秒級，雷射二極體泵浦之被動鎖模Nd:GdVO4種子雷射(波長=1064nm)。其輸出經摻鐿光纖放大，平均功率達28W (重複率≅250MHz)。接著，利用KTP晶體倍頻可產生波長為532nm，功率高達4.3W的綠光。實驗結果，也與理論模擬相吻合。

碩士
國立清華大學
光電工程研究所
100
In this thesis, we designed, constructed and characterized a high-power master oscillator power amplifier system using a dual-stage ytterbium doped fiber amplifier. A diode-pumped solid-state passively mode-locked Nd:GdVO4 laser is the seed laser. For the preamplifier stage, the 10 μm core Yb-doped fiber amplifier is used. For the main amplifier stage, the 30 μm core Yb-doped fiber amplifier is used. After amplification, we can achieve over 60 W output power of 1064 nm signal with pulse width of ~ 10 picosecond (repetition rate ~ 250 MHz). The amplified pulses exhibit excellent beam quality (M2 ~ 1.6). The experimental results are in good agreement with theoretical and predictions.

碩士
國立清華大學
光電工程研究所
102
In this thesis, we demonstrated the chirped pulse amplification (CPA) of a high-power ytterbium-doped fiber amplifier at wavelength of 1064 nm without a stretcher. The all-normal dispersion (ANDi) passively mode-locked fiber laser is used to generate highly chirped seed pulse. Therefore, the pulse stretcher could be optional. The spectrum bandwidth of our ANDi fiber laser is 9 nm which can support 185-fs-width pulses. The actual output pulses width is 11.7 ps. In this case, it is equivalent to -60 times stretching of the seed pulses to reduce the peak power. After amplification, the output signal power can achieve ~1 W with pulse width of 20 picosecond (repetition rate ~ 15 MHz). The output power is basically limited by stimulated Raman scattering (SRS), which reduces the gain of the signal power. After compression by the gratings pair, the output peak power was shown to be 25 kW with a compression ratio ~ 25 (~900 fs). In the meantime, the power loss of the compressor is around 50%. Further, the compressed-pulse was frequency doubled by a type-I critically phase-matched (CPM) Lithium Triborate (LBO) crystal with optimal focal parameter of ξ~ 1.5. With 370 mW of fundamental light, we can generate 88 mW of green output (λ= 532 nm) with conversion efficiency of 23% which is much higher than that achieved with our picosecond laser system (10%). Power scaling is possible but requires introducing second amplification stage with larger mode-field-diameter active fiber or increasing the stretching ratio before the amplification.