Pu Tangyang   Liu Wenwen   Wang Yueliang   Pan Xiaoming   Chen Leiqing   Liu xiaofeng  

      摘要 + 此论文可免费阅读 (可能需要登录)

The laser shock processing implemented by the laser induced high-pressure plasma which propagates into the sample as a shockwave is innovatively applied as a post-processing technique on the HfO₂/SiO₂ multilayer coatings for first time. The pure mechanical post-processing has evidenced a considerable promotion effect of laser induced damage threshold increased by about 4.6 times with appropriate processing parameters. The promotion mechanism was confirmed to be the comprehensive modification of the intrinsic defects and the mechanical properties, which made the applicability of this novelty post-processing technique on various types of coatings possible. Based on the experimental fact, an interaction equation about the plasma pressure was established, which clarified the existence of the critical pressure and provided a theoretical basis for selecting optimal processing parameters. Besides the further clarification of the underlying damage mechanism, the laser shock post-processing provides a promising technique to realize the comprehensive and effective improvement of the laser induced damage resistance of coatings.

       PDF全文 (下载：0)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Huang Lei   Wang De'en   Zhang Xin   Dai Wanjun   Yang Ying   Deng Xuewei   chen lin   Xie Dong   Hu Dongxia   Jing Feng   Yang Zeping   Qiang Yuan   Wei Xiaofeng   Zhu Qihua   zheng wanguo   Zhang Xiaomin  

      摘要 + 此论文可免费阅读 (可能需要登录)

A 1178J near diffraction limited 527nm laser is realized in a complete closed loop adaptive optics (AO) controlled off-axis multi-pass amplification laser system. Generated from a fiber laser and amplified by the pre-amplifier and the main-amplifier, a 1053nm laser beam with the energy of 1900J is obtained and converted to 527nm laser beam by a KDP crystal with 62% conversion efficiency, 1178J and 7.93 times diffraction limited (DL) beam quality. By using a complete closed loop AO configuration, the static and dynamic wavefront distortions of the laser system are measured and compensated. After correction, the diameter of the circle enclosing 80% energy is improved remarkably from 7.93DL to 1.29DL. The focal spot is highly concentrated and the 1178J, 527nm near diffraction limited laser is achieved.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Qian Xinlei   Fan Wei   Lu Xing   Wang Xiaochao  

      摘要 + 此论文可免费阅读 (可能需要登录)

Abstract Based on the pulse-shaping unit in front-end of high-power laser facility, we propose a new hybrid scheme in closed-loop control system including wavelet threshold de-noising (WTD) for pretreatment and first derivative adaptive smoothing filter (FDASF) for smooth pulse recovery, so as to effectively eliminate the influence of electrical noise and FM-to-AM modulation in the time-power curve, and enhance the calibration accuracy of the pulse shape in the feedback control system. The related simulation and experiment results show that the proposed scheme can obtain better shaping effect on high contrast temporal shape in comparison with the cumulative average algorithm (CAA), Orthogonal Matching Pursuit (OMP) combined with traditional smoothing filter (TSF). The implementation of the hybrid scheme mechanism increased the signal to noise ratio (SNR) of laser pulse from about 11 dB to 30dB, and the filtered pulse is smooth without modulation, the smoothness is about 98.8%.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Nam Sang-Hoon   Nagar Garima   Dempsey Dennis   Novak Ondrej   Shim Bonggu   Hong Kyung-Han  

      摘要 + 此论文可免费阅读 (可能需要登录)

We present the experimental and numerical investigations of high-energy mid-infrared filamentation with multi-octave-spanning supercontinuum generation (SCG), pumped by a 2.4 μm, 250 fs Cr:ZnSe chirped-pulse laser amplifier. The SCG is demonstrated in both anomalous and normal dispersion regimes with YAG and polycrystalline ZnSe, respectively. The formation of stable and robust filaments along with the visible-to-mid-infrared SCG is obtained with a pump energy of up to 100 µJ in a 6-mm-long YAG medium. To the best of our knowledge, this is the highest-energy multi-octave-spanning SCG from a laser filament in a solid. On the other hand, the SCG and even-harmonic generation based on random quasi-phase matching (RQPM) are simultaneously observed from the single filaments in a 6-mm-long polycrystalline ZnSe medium with a pump energy of up to 15 µJ. The numerical simulations based on unidirectional pulse propagation equation and RQPM show good agreement with the measured multi-octave-spanning SCG and even-harmonic generation. They also reveal the temporal structure of mid-IR filaments, such as soliton-like self-compression in YAG and pulse broadening in ZnSe.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

song enmao   Zhu Guangzhi   Wang Hailin   chen hantian   qian yefeng   Aleksei Kozlov   Zhu Xiao  

      摘要 + 此论文可免费阅读 (可能需要登录)

We present a 2 μm Tm:YAG disk laser multi-pass pumped by 1 μm laser. The competition transitions of up conversion (UC) and excited state absorption (ESA) are analyzed in detail based on a numerical model accounting stimulated emission, fluorescence, non-radiative decay, UC and ESA, showing good agreement with experiment. The proportions and fractional thermal loads of all transitions are derived quantitatively. The results show that UC and ESA are critical in Tm:YAG disk lasers, resulting in the absorbed pump power and temperature decreased after lasing for two different thickness of disk. In addition, although the absorbed pump power of 0.5 mm disk is lower than 1 mm case, its relatively weak UC and ESA and low total fractional thermal load can improve laser performances. A 0.5 mm Tm:YAG disk laser thus delivered the maximum output power of 1.05 W with beam quality of Mx2 = 2.02 and My2 = 2.03.

       PDF全文 (下载：4)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Du Ai   Ma Yi   Liu Mingfang   Zhang Zhihua   Cao Guangwei   Li Hongwei   Wang Ling   Shen Jun   Zhou Bin  

      摘要 + 此论文可免费阅读 (可能需要登录)

As an attractive collector medium for hypervelocity particles, combined with outstanding physical properties and suitable compositional characteristics, SiO2 aerogel has been deployed on outer space missions and laser shock-loaded collection experiments. In this paper, impact experiments were conducted in order to understand the penetration process of irregular grains, irregular Al2O3 grains with different sizes and speed (~110um@7km/s, ~251um@2.3km/s) at various density silica aerogels. By classifying shapes of projectile residues and track, the morphology of tracks was analyzed. It was observed that there were several kinds of typical tracks in the penetration of irregular grains, accompanied by residues with the shapes of Near-Sphere, Polyhedron, Streamlined body Wedge and Rotator. The rotational behavior was demonstrated by the final status of one flake projectile as a direct evidence. Also, there was no obvious relationship between track length and experimental parameters, which may be caused by the uncertain interaction between aerogels and irregular particles. In addition, it confirmed the existence of fragmentation, melting situation by observing the shape of the impact entrance hole. At the same time, optical coherence tomography was used to observe the detail of tracks clearly, which provided a method to character the tracks nondestructively.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Körner Jörg   Jambunathan Venkatesan   Yue Fangxin   Reiter Jürgen   Slezak Ondrej   Navratil Petr   Paul David Samuel   Lucianetti Antonio   Hein Joachim   Mocek Tomas   Kaluza Malte  

      摘要 + 此论文可免费阅读 (可能需要登录)

We present a diode pumped, electro-optically q-switched Tm:YAG laser with a cryogenically cooled laser crystal at 120\,K. Output pulses with up to 2.55\,mJ and 650\,ns length were demonstrated in an actively Q-switched configuration with a repetition rate of 1\,Hz. By using cavity dumping the pulse duration was shortened to 18\,ns with an only slightly lower output energy of 2.22\,mJ. Furthermore, using a simplified rate equation model, we discuss design constraints on the pump fluence in a pulse pump approach for Tm:YAG to maximize the energy storage capability at given pump power.

       PDF全文 (下载：0)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Danson Colin   McKenna Paul  

      摘要 + 此论文可免费阅读 (可能需要登录)

David Neely was an internationally recognised scientist who formed collaborations and friendships across the world. His passion for his work always shone through. He always made time for early career scientists and became a mentor and supervisor to many. He was an active Editorial Board Member of the international journal High Power Laser Science and Engineering. Sadly, David was taken from us much too early. In this Editorial we pay tribute to his work through his publications in the journal.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Feng Jie   Li Yifei   Wang Jingguang   Li Dazhang   Zhu Changqing   Tan JunHao   geng xiaotao   Liu Feng   Chen Liming  

      摘要 + 此论文可免费阅读 (可能需要登录)

We demonstrate an all-optical method for controlling the transverse motion of ionization injected electron beam in laser plasma accelerator by utilizing the transversely asymmetrical plasma wakefield. The laser focus shape can control the distribution of transversal wakefield. When the laser focus shape is changed from the circular to the slantingly elliptic in experiment, the electron beam profiles change from ellipse and occur three typical shapes. The 3D-PIC simulation result agrees well with experiment, and it shows the trajectories of these accelerated electrons change from undulation to helix. Such an all-optical method could be useful for convenient control of the transverse motion of an electron beam, which results in synchrotron radiation with orbit angular momentum.

       PDF全文 (下载：4)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Han Bo   Wang Feilu   Salzmann David   Zhong Jiayong   Zhao Gang  

      摘要 + 此论文可免费阅读 (可能需要登录)

In this paper, we present a reanalysis of the silicon He-α X-ray spectrum emission in Fujioka et al.2009 photoionization experiment. The computations have been carried out with our radiative-collisional code, RCF. The central ingredients of our computations are accurate atomic data, inclusion of satellite lines from doubly excited states, as well as accounting for the reabsorption of the emitted photons on their way to the spectrometer. With all these elements, the simulated spectrum turns out to be in good agreement with the experimental one.

       PDF全文 (下载：2)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Gizzi Leonida   Labate Luca   Baffigi Federica   Brandi Fernando   Bussolino GC   Fulgentini Lorenzo   Koester Petra   Palla Daniele  

      摘要 + 此论文可免费阅读 (可能需要登录)

We present the main features of the ultrashort, high intensity laser installation at the ILIL Laboratory including laser, beam transport and target area specifications. The Laboratory was designed to host laser-target interaction experiments at > 220 TW peak power, in flexible focusing configurations, with ultrarelativistic intensity on target. Specifications have been established via dedicated optical diagnostic assemblies and commissioning interaction experiments. Here we give a summary of laser specifications available to users, including spatial, spectral and temporal contrast features. The layout of the experimental target areas is presented, with attention to available configurations of laser focusing geometries and diagnostics. We finally discuss radiation protection measures and mechanical stability of the laser focal spot on target.

       PDF全文 (下载：0)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Quere F.   Vincenti Henri  

      摘要 + 此论文可免费阅读 (可能需要登录)

The quantum vacuum plays a central role in Physics. Quantum Electrodynamics (QED) predicts that the properties of the fermionic quantum vacuum can be probed by extremely large electromagnetic fields. The typical field amplitudes required correspond to the onset of the ‘optical breakdown’ of this vacuum, expected at light intensities >4.7x10^29 W/cm^2. Approaching this ‘Schwinger limit’ would enable testing major but still unverified predictions of QED. Yet, the Schwinger limit is seven orders of magnitude above the present record in light intensity achieved by high-power lasers. To close this considerable gap, a promising paradigm consists in reflecting these laser beams off a mirror in relativistic motion, to induce a Doppler effect that compresses the light pulse in time down to the attosecond range, and converts it to shorter wavelengths, which can then be focused much more tightly than the initial laser light. This however faces a major experimental hurdle: how to generate such relativistic mirrors? In this article, we explain how this challenge could nowadays be tackled by using so-called ‘relativistic plasma mirrors’. We argue that approaching the Schwinger limit in the coming years by applying this scheme to the latest generation of PetaWatt-class lasers is a challenging but realistic objective.

       PDF全文 (下载：2)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Gu Yanjun   Bulanov Sergei  

      摘要 + 此论文可免费阅读 (可能需要登录)

Magnetic reconnection driven by laser plasma interactions attracts great interests in the recent decades. Motivated by the rapid development of the laser technology, the ultra strong magnetic field generated by the laser-plasma accelerated electrons provides unique environment to investigate the relativistic magnetic field annihilation and reconnection. It opens a new way for understanding relativistic regimes of fast magnetic field dissipation particularly in space plasmas, where the large scale magnetic field energy is converted to the energy of the nonthermal charged particles. Here we review the recent results in relativistic magnetic reconnection based on the laser and collisionless plasma interactions. The basic mechanism and the theoretical model are discussed. Several proposed experimental setups for relativistic reconnection research are presented.

       PDF全文 (下载：0)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Lamprou Theocharis   Liontos Ioannis   Papadakis Nikolaos   Tzallas Paraskevas  

      摘要 + 此论文可免费阅读 (可能需要登录)

Non-classical light sources have a vital role in quantum optics as they offer a unique resource for studies in quantum technology. However, their applicability is restricted by their low intensity, while the development of new schemes producing intense non-classical light is a challenging task. In this perspective article, we discuss potential schemes that could be used towards the development of high photon flux non-classical light sources and their future prospects in non-linear optics.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Lv Zhiguo   Yang Zhi   Li Qianglong   Li Feng   yang Xiaojun   Wang Yishan   Zhao Wei  

      摘要 + 此论文可免费阅读 (可能需要登录)

In this paper, we innovatively conduct a porro prism based beam pointing stability promotion technique research and realize high-performance rod-type photonic crystal fiber based chirped pulse amplification (CPA) system; mainly including a frequency-reduced all-fiber pre-amplification stage, photonic crystal rod based main amplification stage, and 1600 lines/mm transmission grating-pair compressor. Laser output with average power of 50 W, repetition rates of 500 kHz, pulse energy of 100 uJ, pulse duration of 830 fs, beam quality of M2<1.3, power fluctuation of 0.55% RMS and beam pointing drift of 19 urad/℃ over 8 h, is realized. The high-performance laser system has an enormous application potential in fundamental research and precision manufacturing fields.

       PDF全文 (下载：3)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Lureau Francois   Matras Guillaume   CHALUS OLIVIER   Derycke Christophe   Morbieu Thomas   Radier Christophe   Casagrande Olivier   Laux Sebastien   Ricaud Sandrine   Rey Gilles   Pellegrina Alain   Richard Caroline   Boudjemaa Laurent   Simon Boisson Christophe   Baleanu Andrei   Banici Romeo   Gradinariu Andrei   Caldararu Constantin   de Boisdeffre Bertrand   Ghenuche Petru   Naziru Andrei   Kolliopoulos Georgios   Neagu Liviu   Dabu Razvan   Dancus Ioan   Ursescu Daniel  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on a two-arm hybrid high power laser system (HPLS) able to deliver 2×10 PW femtosecond pulses, developed at the Bucharest-Magurele Extreme Light Infrastructure – Nuclear Physics facility. A hybrid Ti:sapphire chirped pulse amplifier (CPA)/BBO crystals picosecond optical parametric CPA (OPCPA) Front-End, with a crossed polarized wave filter (XPW) in between these stages, has been developed to produce 10 mJ laser pulse energy, at 10 Hz repetition rate, with more than 70 nm spectral bandwidth and high intensity contrast, in the range of 1013:1. High energy Ti:sapphire amplifier stages of both arms were seeded from this common Front-End. The final booster amplifier, equipped with a 200 mm diameter Ti:sapphire crystal, has been pumped by six 100 J nanosecond frequency doubled Nd:glass lasers, at 1 pulse/minute repetition rate, to deliver more than 300 J output energy. Considering the 10 PW compressor transmission efficiency of 74% and a compressed pulse duration of 22.7 fs, obtained at attenuated input energy level, we demonstrated that the dual-arm HPLS has the capacity to generate 10 PW peak power femtosecond pulses. The reported results represent the cornerstone of the ELI-NP 2×10 PW femtosecond laser facility, devoted to fundamental and applied nuclear physics research.

       PDF全文 (下载：2)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Wang Dahui   Shou Yinren   Wang Pengjie   Liu Jianbo   Mei Zhusong   Cao Zhengxuan   Zhang Jianmin   Yang Pengling   Feng Guobin   Chen Shiyou   Zhao YIng   Schreiber Joerg   Ma Wenjun  

      摘要 + 此论文可免费阅读 (可能需要登录)

Single-shot laser-induced damage threshold (LIDT) measurements of multi-type free-standing ultrathin foils were performed in vacuum environment for 800 nm laser pulses with durations τ ranging from 50 fs to 200 ps. Results show that the laser damage threshold fluences (DTFs) of the ultrathin foils are significantly lower than those of corresponding bulk materials. Wide band gap dielectric targets such as SiN and formvar have larger DTFs than those of semiconductive and conductive targets by 1-3 orders of magnitude depending on the pulse duration. The damage mechanisms for different types of targets are studied. Based on the measurement, the constrain of the LIDTs on the laser contrast is discussed.

       PDF全文 (下载：17)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Batani Dimitri   Jakubowska Katarzyna   Mancelli Donaldi   Benocci Roberto   Trelat Jocelain   Martynenko Artem   Verona Claudio   Aliverdiev Abutrab   Borm Bjorn   Neumayer Paul   Rosmej O   Molineri Anais  

      摘要 + 此论文可免费阅读 (可能需要登录)

In this work we present experimental results on the behavior of diamond at Megabar pressure. The experiment was performed using the PHELIX facility at GSI in Germany to launch a planar shock into solid multi-layered diamond samples. The target design allows to measure shock velocity in diamond and in two metal layers and to measure the free surface velocity after shock breakout. As diagnostics, we used two VISAR systems (velocity interferometry system for any reflector). Our measurements show that for the pressures obtained in diamond (between 9 and 3 Mbar), the propagation of the shock induces a reflecting state of the material. Finally experimental results were compared to hydrodynamical simulations in which we used different equations of state, showing compatibility with dedicated Sesame tables for diamond.

       PDF全文 (下载：3)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Chen Yizhu   Yao Tianfu   Xiao Hu   Leng Jinyong   Zhou Pu  

      摘要 + 此论文可免费阅读 (可能需要登录)

In this paper, we report a 2-kW all-fiberized Raman fiber amplifier with efficient brightness enhancement based on the graded-index fiber. The maximum output power reaches up to 2.034 kW centered at 1130 nm, with a conversion efficiency of 79.35% with respect to the injected pump power. To the best of our knowledge, this is the highest conversion efficiency obtained for any Raman laser systems using graded-index fiber. An optimized fiber combiner adopting the graded-index fiber as the pigtail fiber is fabricated, enabling the preservation of the seeding brightness in the core-pumped Raman fiber amplifier, and further enhancing the ultimate brightness of the output laser after amplification. At the maximum output power, the beam quality parameter M² is 2.8 corresponding to a signal-to-pump brightness enhancement factor of 11.2. As far as we know, we obtain the highest brightness enhancement among Raman fiber lasers of over 100 W, and the best beam quality for graded-index Raman fiber lasers of over 150 W.

       PDF全文 (下载：7)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Zhou Lian   Liu Yang   Xie Gehui   Gu Chenglin   Deng Zejiang   Zhu Zhiwei   Ouyang Cheng   Zuo Zhong   Luo Daping   Wu Bin   Chen Kunfeng   Li Wenxue  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on the generation of mid-infrared (mid-IR) frequency comb with a maximum average output power of 250 mW and tunability in the 2.7-4.0 μm region. The approach is based on a single stage difference frequency generation (DFG) starting from a compact Yb-doped fiber laser system. The repetition rate of near-infrared (NIR) comb is locked at 75 MHz. The phase noise of repetition rate in the offset-free mid-IR comb system is measured and analyzed. Except for the intrinsic of NIR comb, environmental noise at low frequency and quantum noise at high frequency from the amplifier chain and nonlinear spectral broadening are the main noise source of broadening the linewidth of comb teeth, which limit the precision of mid-IR dual-comb spectroscopy.

       PDF全文 (下载：10)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

GALLETTI MARIO   Oliveira Pedro   Galimberti Marco   Ahmad Munadi   Archipovaite Giedre   Booth Nicola   Dilworth Emerald   Frackiewicz Andy   Winstone Trevor   Musgrave Ian   Hernandez-Gomez Christina  

      摘要 + 此论文可免费阅读 (可能需要登录)

A petawatt facility fully based on noncollinear Optical Parametric Chirped Pulse Amplification (NOPCPA) technology, Vulcan OPPEL (Vulcan OPCPA PEtawatt Laser), is presented. This system will be coupled with the existing hybrid-CPA/OPCPA VULCAN laser system (500 J, 500 fs beamline; 250 J, ns regime beamline) based on Nd:Glass amplification. Its pulse duration (20 times shorter) combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for the longer pulses and their interactions with targets. Furthermore, the system, designed and mainly dedicated to electron beam generation, is not exclusive of other experimental campaigns devoted to particle acceleration and optical radiation detection. In this communication, we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section. Finally, we present experimental results and details on our commissioned NOPCPA picosecond front end, delivering 1.5 mJ, ~180 nm (1/e2) of bandwidth compressed to sub-15 fs.

       PDF全文 (下载：4)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Alkhimova Maria   Ryazantsev Sergey   Skobelev Igor   Boldarev Alexey   Feng Jie   Lu Xin   Chen Liming   Pikuz SA  

      摘要 + 此论文可免费阅读 (可能需要登录)

In this work we optimized a clean, versatile, compact source of soft X-ray radiation (E x - ray ~ 3 keV) with an yield per shot up to 7 × 10^11 photon/shot in a plasma generated by interaction of high-contrast femtosecond laser pulses of relativistic intensity (Ilas ~ 10^18 - 10^19 W/cm^2) with supersonic argon gas jets. Using high-resolution X-ray spectroscopy approaches, the dependence of main characteristics (temperature, density, ionization composition) and the emission efficiency of the X-ray source on laser pulse parameters and properties of the gas medium were studied. The optimal conditions, when an x-ray photon yield reached maximum, have been found when the argon plasma has an electron temperature of Te ~ 220 eV, an electron density of Ne ~ 6 × 10^19 cm-3 and an average charge of Z ~ 14. In such a plasma, a coefficient of conversion to X-ray radiation with energies Ex - ray ~ 3.1 (±0.2) keV reached 8.57 × 10^-5, no processes leading to the acceleration of electrons to MeV energies occurred. It was found that the efficiency of X-ray emission of this plasma source is mainly determined by the focusing geometry, but angular distribution of X-ray radiation is isotropic.

       PDF全文 (下载：1)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Banerjee Saumyabrata   Mason Paul   Phillips Jonathan   Smith Jodie   Butcher Thomas   Spear Jacob   De Vido Mariastefania   Quinn Gary   Clarke Danielle   Ertel Klaus   Hernandez-Gomez Christina   Edwards Chris   Collier John  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on the successful demonstration of a 150 J nanosecond pulsed cryogenic gas cooled, diode pumped multi slab Yb:YAG laser operating at 1 Hz. To the best of our knowledge, this is the highest energy ever recorded for a diode pumped laser system.

       PDF全文 (下载：3)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Shen YingJie   Qian Chuanpeng   Duan Xiaoming   Lan Ruijun  

      摘要 + 此论文可免费阅读 (可能需要登录)

We demonstrated a high power long-wave infrared laser based on a polarization beam coupling technique. An average output power at 8.3 μm of 7.0 W was achieved at maximum available pump power of 107.6 W, corresponding with an optical to optical conversion of 6.5%. The coupling efficiency of the polarization coupling system was calculated to be approximately 97.2%. With idler single resonance operation, a good beam quality factor of ~1.8 combined with an output wavelength of 8.3 μm was obtained at the maximum output power.

       PDF全文 (下载：2)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Wang Wei   Sun Di   Du Xiao   Guo Jie   Liang Xiaoyan  

      摘要 + 此论文可免费阅读 (可能需要登录)

A simple, compact, double-pass pumped Nd:YVO₄ thin disk laser is demonstrated. Its continuous-wave performance with different Nd doping concentration and thickness is investigated experimentally. The maximum output power of 17.7 W is achieved by employing a 0.5 at.% doped sample, corresponding to an optical-to-optical efficiency of 46% with respect to the absorbed pump power. Meanwhile, a numerical analysis and an experimental study of the temperature distribution, and thermal lens effect of Nd:YVO₄ thin disk are presented considering the influence of energy transfer upconversion effect and the temperature dependence of the thermal conductivity tensor. The simulated results are in good agreement with the experimental results.

       PDF全文 (下载：5)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Wang Meng   Huang Yijian   Song Zongpeng   Wei Jincheng   Pei Jihong   Ruan Shuangchen  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulse, relying on the transmission semiconductor saturable absorber (SESA) and carbon nanotubes (CNTs-PVA) film, separately. Meanwhile, a section of SMF-MMF-SMF fiber structure multimode interferometer with transmission peak wavelength of ~2003 nm was used as a wavelength selector to fix the laser wavelength. When the SESA acted as SA, the mode-locked fiber laser has maximum output power of ~461 mW with pulse energy of ~0.14 μJ and pulse duration of ~9.14 ns. In CNTs-film based mode-locked fiber laser, stable mode-locked pulses with the maximum output power of ~46 mW, pulse energy of ~26.8 nJ and pulse duration of ~9.3 ns were obtained. To the best of our knowledge, our experiments demonstrated the first 2 μm region “real” SA-based dissipative soliton resonance with the highest mode-locked pulse energy from “real” SA-based all-fiberized resonator.

       PDF全文 (下载：5)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Zhang Jiaji   Wu Duanduan   Zhao Ruwei   Wang Rongping   Dai Shixun  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on the investigation of intermode beating mode-locking (IBML) pulse generation in a simple all fiber Tm3+-doped double clad fiber laser (TDFL). This IBML TDFL is implemented by matching longitudinal-mode frequency between 793 nm laser and TDFL without extra mode-locker. The central wavelength of ~1983 nm, the fundamental pulse frequency of ~9.6 MHz, and the signal to noise ratio (SNR) of >50 dB is achieved in this IBML TDFL. With laser cavity optimization, the IBML TDFL can finally generate an average output power of 1.03 W with corresponding pulse energy of ~107 nJ. These results can provide an easily accessible way to develop compact large energy, high power TDFLs.

       PDF全文 (下载：4)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Tian Wenlong   Wang Geyang   Zhang Dacheng   Zhu Jiangfeng   Wang Zhaohua   Xu Xiaodong   Xu Jun   Wei Zhiyi  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on the study of a single-mode fiber laser-pumped mode-locked Yb:CALYO lasers via using a passive saturable absorber and Kerr-lens mode-locking technique, respectively. Up to 3.1-W average power with 103-fs pulse duration is obtained from the passive mode-locking, and down to 36-fs pulse duration with more than 2-W average power is achieved by the pure Kerr-lens mode-locking, which is to the best of our knowledge, the highest average power from a reported sub-40 fs Yb-based solid-state oscillator.

       PDF全文 (下载：6)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Liu Jinsheng   Ma Jingui   Wang Jing   Yuan Peng   Xie Guoqiang   Qian Liejia  

      摘要 + 此论文可免费阅读 (可能需要登录)

High-power femtosecond lasers beyond 5 μm are attractive for strong-field physics with mid-infrared (IR) fields but are difficult to scale up. In optical parametric chirped-pulse amplification (OPCPA) at mid-IR wavelengths, a nonlinear crystal is vital, and its transmittance, dispersion, nonlinear coefficient, and size determine the achievable power and wavelength. OPCPA beyond 5 μm routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range. However, the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts. In this paper, we design a terawatt-class OPCPA system at 5.2 μm based on a new kind of oxide crystal of La₃Ga_5.5Nb_0.5O₁₄ (LGN). The extended transparent range, high damage threshold, superior phase-matching characteristics, and large size of LGN enable the generation of 0.13-TW seven-cycle pulses at 5.2 μm. This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser, offering the performance characteristics of high power, a high repetition rate, and a stable carrier-envelope phase.

       PDF全文 (下载：14)        High Power Laser Sci. Eng. ，年第卷第期 pp.      

Cheng Xi   Peng Wang   Xiao Li   Liu Zejin  

      摘要 + 此论文可免费阅读 (可能需要登录)

We report on a new scheme for efficient continuous-wave (CW) mid-infrared generation using difference frequency generation (DFG) inside a PPLN-based optical parametric oscillator (OPO). The pump sources were two CW fiber lasers fixed at 1018 nm and 1080 nm. One worked as the assisted laser to build parametric oscillation and generate oscillating signal beam while the other worked at low power (≤3 W) for inducing DFG between it and the signal beam. The PPLN temperature was properly adjusted for enabling OPO and DFG synchronously meet phase-matching conditions. At last, both low-power 1018 nm and 1080 nm pump beams were successfully converted to 3.1 μm and 3.7 μm idler beams separately. The conversion efficiency of 1018 nm and 1080 nm pumped DFG reached 20% and 15% separately while their slope efficiency reached 19.6% and 15%. All these data were comparable with the OPOs pumped by themselves and never realized before in traditional CW DFG schemes. The results reveal that the high efficiency frequency down conversion can be achieved with low-power near-infrared pump source.

       PDF全文 (下载：2)        High Power Laser Sci. Eng. ，年第卷第期 pp.