The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power toleran...The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power tolerance and large modulation depth. Here, we report a type of microfiber-based MoTe2 SA fabricated by the magnetron-sputtering deposition （MSD） method. High-energy wave-breaking free soliton pulses were generated with pulse duration/pulse energy/average output power of 229 fs/2.14 nJ/57 mW in the 1.5 μm regime and 1.3 ps/13.8 nJ/ 212 mW in the 2 μm regime, respectively. To our knowledge, the generated soliton pulses at 1.5μm had the shortest pulse duration and the highest output power among the reported erbium-doped fiber lasers mode locked by transition metal dichalcogenides. Moreover, this was the first demonstration of a MoTe2-based SA in fiber lasers in the 2 ltm regime, and the pulse energy/output power are the highest in the reported thulium-doped fiber lasers mode locked by two-dlmensional materials. Our results suggest that a microfiber-based MoTe2 SA could be used as an excellent photonic device for ultrafast pulse generation, and the MSD technique opens a promising route to produce a high-performance SA with high power tolerance and large modulation depth, which are beneficial for high-energy wave-breaking free pulse generation.展开更多
The objective of the Apollon 10 PW project is the generation of 10 PW peak power pulses of 15 fs at 1 shot min^(-1). In this paper a brief update on the current status of the Apollon project is presented, followed by ...The objective of the Apollon 10 PW project is the generation of 10 PW peak power pulses of 15 fs at 1 shot min^(-1). In this paper a brief update on the current status of the Apollon project is presented, followed by a more detailed presentation of our experimental and theoretical investigations of the temporal characteristics of the laser. More specifically the design considerations as well as the technological and physical limitations to achieve the intended pulse duration and contrast are discussed.展开更多
We fabricate a free-standing few-layer molybdenum disulfide （MoS2）-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-lo...We fabricate a free-standing few-layer molybdenum disulfide （MoS2）-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS2 material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications.展开更多
Since the advent of femtosecond lasers,performance improvements have constantly impacted on existing applications and enabled novel applications.However,one performance feature bearing the potential of a quantum leap ...Since the advent of femtosecond lasers,performance improvements have constantly impacted on existing applications and enabled novel applications.However,one performance feature bearing the potential of a quantum leap for high-field applications is still not available:the simultaneous emission of extremely high peak and average powers.Emerging applications such as laser particle acceleration require exactly this performance regime and,therefore,challenge laser technology at large.On the one hand,canonical bulk systems can provide pulse peak powers in the multi-terawatt to petawatt range,while on the other hand,advanced solid-state-laser concepts such as the thin disk,slab or fibre are well known for their high efficiency and their ability to emit high average powers in the kilowatt range with excellent beam quality.In this contribution,a compact laser system capable of simultaneously providing high peak and average powers with high wall-plug efficiency is proposed and analysed.The concept is based on the temporal coherent combination(pulse stacking)of a pulse train emitted from a high-repetition-rate femtosecond laser system in a passive enhancement cavity.Thus,the pulse energy is increased at the cost of the repetition rate while almost preserving the average power.The concept relies on a fast switching element for dumping the enhanced pulse out of the cavity.The switch constitutes the key challenge of our proposal.Addressing this challenge could,for the first time,allow the highly efficient dumping of joule-class pulses at megawatt average power levels and lead to unprecedented laser parameters.展开更多
Optical parametric chirped-pulse amplification(OPCPA) [Dubietis et al., Opt. Commun. 88, 437(1992)] implemented by multikilojoule Nd:glass pump lasers is a promising approach to produce ultraintense pulses(>1023 W/...Optical parametric chirped-pulse amplification(OPCPA) [Dubietis et al., Opt. Commun. 88, 437(1992)] implemented by multikilojoule Nd:glass pump lasers is a promising approach to produce ultraintense pulses(>1023 W/cm2).Technologies are being developed to upgrade the OMEGA EP Laser System with the goal to pump an optical parametric amplifier line(EP OPAL) with two of the OMEGA EP beamlines. The resulting ultraintense pulses(1.5 kJ, 20 fs,1024 W/cm2) would be used jointly with picosecond and nanosecond pulses produced by the other two beamlines. A midscale OPAL pumped by the Multi-Terawatt(MTW) laser is being constructed to produce 7.5-J, 15-fs pulses and demonstrate scalable technologies suitable for the upgrade. MTW OPAL will share a target area with the MTW laser(50 J, 1 to 100 ps), enabling several joint-shot configurations. We report on the status of the MTW OPAL system, and the technology development required for this class of all-OPCPA laser system for ultraintense pulses.展开更多
Metals in nature exhibit a mediocre wettability and a high optical reflectance from the visible region to the infrared. This Letter reports that, by formation of nano- and microscale structures via a simple raster sca...Metals in nature exhibit a mediocre wettability and a high optical reflectance from the visible region to the infrared. This Letter reports that, by formation of nano- and microscale structures via a simple raster sca.nning of a focused femtosecond laser pulse without any further treatment, structured aluminum and nickel surfaces exhibit combined features of superhydrophobicity with a contact angle of 155.5°, and a high optical absorption with a rcflectivity of several percent over a broad spectral range （0.2-2.5μm）. Thus, a multifunctional structured metal surface that integrates superhydrophobicity and a high broadband absorptivity has been easily realized by one-step femtosecond laser processing.展开更多
We present a high-peak-power,near-infrared laser system based on optical parametric chirped pulse amplification pumped by a home-built picosecond pumping laser,which can generate over 40 mJ energy at 1450 nm center wa...We present a high-peak-power,near-infrared laser system based on optical parametric chirped pulse amplification pumped by a home-built picosecond pumping laser,which can generate over 40 mJ energy at 1450 nm center wavelength and operate at 100 Hz repetition rate.Subsequently,the chirped laser pulses are compressed down to 60 fs with 26.5 mJ energy,corresponding to a peak power of 0.44 TW. This high-energy,long-wavelength laser source is highly suitable for driving various nonlinear optical phenomena,such as high-order harmonic generation and high-flux coherent extreme ultraviolet/soft X-ray radiation.展开更多
In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can gene...In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can generate high-intensity THz pulses(a)those with large-aperture dipoles and(b)those with interdigitated electrodes.We will first describe the principles of THz generation from PCAs.The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized.We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with widebandgap semiconductor substrates.Then,we will explain the evolution of LAPCA with interdigitated electrodes,which allows one to reduce the photoconductive gap size,and thus obtain higher bias fields while applying lower voltages.We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by ampli-fied lasers.Finally,we will discuss the future perspectives of THz pulse generation using LAPCAs.展开更多
The performance of ultrafast semiconductor disk lasers has rapidly advanced in recent decades.The strong interest from industry for inexpensive,compact,and reliable ultrafast laser sources in the picosecond and femtos...The performance of ultrafast semiconductor disk lasers has rapidly advanced in recent decades.The strong interest from industry for inexpensive,compact,and reliable ultrafast laser sources in the picosecond and femtosecond domains has driven this technology toward commercial products.Frequency metrology and biomedical applications would benefit from sub-200-femtosecond pulse durations with peak powers in the kilowatt range.The aim of this review is to briefly describe the market potential and give an overview of the current status of mode-locked semiconductor disk lasers.Particular focus is placed on the ongoing efforts to achieve shorter pulses with higher peak powers.展开更多
Ultrafast fiber lasers are in great demand for various applications, such as optical communication, spectroscopy,biomedical diagnosis, and industrial fabrication. Here, we report the highly stable femtosecond pulse ge...Ultrafast fiber lasers are in great demand for various applications, such as optical communication, spectroscopy,biomedical diagnosis, and industrial fabrication. Here, we report the highly stable femtosecond pulse generation from a MXene mode-locked fiber laser. We have prepared the high-quality Ti_3C_2 T_x nanosheets via the etching method, and characterized their ultrafast dynamics and broadband nonlinear optical responses. The obvious intensity-and wavelength-dependent nonlinear responses have been observed and investigated. In addition, a highly stable femtosecond fiber laser with signal-to-noise ratio up to 70.7 dB and central wavelength of 1567.3 nm has been delivered. The study may provide some valuable design guidelines for the development of ultrafast, broadband nonlinear optical modulators, and open new avenues toward advanced photonic devices based on MXenes.展开更多
基金National Natural Science Foundation of China(NSFC)(11704260,61405126,61605122,61775146)Shenzhen Science and Technology Project(JCY20150324141711695,JCYJ20160427105041864,JSGG20160429114438287,KQJSCX20160226194031,JCYJ20160422103744090)+1 种基金Beijing University of Posts and Telecommunications(BUPT)(IPOC2015B003)Natural Science Foundation of Guangdong Province(2016A030310049,2016A030310059)
文摘The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power tolerance and large modulation depth. Here, we report a type of microfiber-based MoTe2 SA fabricated by the magnetron-sputtering deposition （MSD） method. High-energy wave-breaking free soliton pulses were generated with pulse duration/pulse energy/average output power of 229 fs/2.14 nJ/57 mW in the 1.5 μm regime and 1.3 ps/13.8 nJ/ 212 mW in the 2 μm regime, respectively. To our knowledge, the generated soliton pulses at 1.5μm had the shortest pulse duration and the highest output power among the reported erbium-doped fiber lasers mode locked by transition metal dichalcogenides. Moreover, this was the first demonstration of a MoTe2-based SA in fiber lasers in the 2 ltm regime, and the pulse energy/output power are the highest in the reported thulium-doped fiber lasers mode locked by two-dlmensional materials. Our results suggest that a microfiber-based MoTe2 SA could be used as an excellent photonic device for ultrafast pulse generation, and the MSD technique opens a promising route to produce a high-performance SA with high power tolerance and large modulation depth, which are beneficial for high-energy wave-breaking free pulse generation.
基金financial support from the ILE-APOLLON 07-CPER 017-01 contract
文摘The objective of the Apollon 10 PW project is the generation of 10 PW peak power pulses of 15 fs at 1 shot min^(-1). In this paper a brief update on the current status of the Apollon project is presented, followed by a more detailed presentation of our experimental and theoretical investigations of the temporal characteristics of the laser. More specifically the design considerations as well as the technological and physical limitations to achieve the intended pulse duration and contrast are discussed.
文摘We fabricate a free-standing few-layer molybdenum disulfide （MoS2）-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS2 material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications.
基金This work has been partly supported by the German Federal Ministry of Education and Research(BMBF)under contract 13N12082‘NEXUS’,by the Thuringian Ministry of Education,Science and Culture(TMBWK)under contract 12037-515‘BURST’by the European Research Council under the ERC grant agreement no.[617173]‘ACOPS’+3 种基金by the Deutsche Forschungsgemeinschaft Cluster of Excellence‘Munich-Centre for Advanced Photonics’(munich-photonics.de).AK acknowledges financial support by the Helmholtz-Institute Jena.TE acknowledges financial support by the CarlZeiss-Stiftung.IP and SH acknowledge financial support by the BMBF under PhoNa-Photonische Nanomaterialien,contract number 03IS2101B.
文摘Since the advent of femtosecond lasers,performance improvements have constantly impacted on existing applications and enabled novel applications.However,one performance feature bearing the potential of a quantum leap for high-field applications is still not available:the simultaneous emission of extremely high peak and average powers.Emerging applications such as laser particle acceleration require exactly this performance regime and,therefore,challenge laser technology at large.On the one hand,canonical bulk systems can provide pulse peak powers in the multi-terawatt to petawatt range,while on the other hand,advanced solid-state-laser concepts such as the thin disk,slab or fibre are well known for their high efficiency and their ability to emit high average powers in the kilowatt range with excellent beam quality.In this contribution,a compact laser system capable of simultaneously providing high peak and average powers with high wall-plug efficiency is proposed and analysed.The concept is based on the temporal coherent combination(pulse stacking)of a pulse train emitted from a high-repetition-rate femtosecond laser system in a passive enhancement cavity.Thus,the pulse energy is increased at the cost of the repetition rate while almost preserving the average power.The concept relies on a fast switching element for dumping the enhanced pulse out of the cavity.The switch constitutes the key challenge of our proposal.Addressing this challenge could,for the first time,allow the highly efficient dumping of joule-class pulses at megawatt average power levels and lead to unprecedented laser parameters.
基金supported by the Department of EnergyNational Nuclear Security Administration under Award Number DE-NA0001944+2 种基金the University of Rochesterthe New York State Energy Research and Development Authoritysponsored by an agency of the U.S.Government
文摘Optical parametric chirped-pulse amplification(OPCPA) [Dubietis et al., Opt. Commun. 88, 437(1992)] implemented by multikilojoule Nd:glass pump lasers is a promising approach to produce ultraintense pulses(>1023 W/cm2).Technologies are being developed to upgrade the OMEGA EP Laser System with the goal to pump an optical parametric amplifier line(EP OPAL) with two of the OMEGA EP beamlines. The resulting ultraintense pulses(1.5 kJ, 20 fs,1024 W/cm2) would be used jointly with picosecond and nanosecond pulses produced by the other two beamlines. A midscale OPAL pumped by the Multi-Terawatt(MTW) laser is being constructed to produce 7.5-J, 15-fs pulses and demonstrate scalable technologies suitable for the upgrade. MTW OPAL will share a target area with the MTW laser(50 J, 1 to 100 ps), enabling several joint-shot configurations. We report on the status of the MTW OPAL system, and the technology development required for this class of all-OPCPA laser system for ultraintense pulses.
基金supported by the National 973 Program of China(No.2013CB922404)the National Natural Science Foundation of China(Nos.11074027,61178022,and 11274053)+1 种基金the Funds from Science and Technology Department of Jilin Province(No.20111812),the Project 14KP007the Research Fund for the Doctoral Program of Higher Education of China(Nos.20122216120009,20122216110007,and 20112216120006)
文摘Metals in nature exhibit a mediocre wettability and a high optical reflectance from the visible region to the infrared. This Letter reports that, by formation of nano- and microscale structures via a simple raster sca.nning of a focused femtosecond laser pulse without any further treatment, structured aluminum and nickel surfaces exhibit combined features of superhydrophobicity with a contact angle of 155.5°, and a high optical absorption with a rcflectivity of several percent over a broad spectral range （0.2-2.5μm）. Thus, a multifunctional structured metal surface that integrates superhydrophobicity and a high broadband absorptivity has been easily realized by one-step femtosecond laser processing.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB1603)National Natural Science Foundation of China(Nos.11127901,61521093 and 61635012)+2 种基金International S&T Cooperation Program of China(No.2016YFE0119300)Program of Shanghai Academic/Technology Research Leader(No.18XD1404200)Shanghai Municipal Science and Technology Major Project(No.2017SHZDZX02)
文摘We present a high-peak-power,near-infrared laser system based on optical parametric chirped pulse amplification pumped by a home-built picosecond pumping laser,which can generate over 40 mJ energy at 1450 nm center wavelength and operate at 100 Hz repetition rate.Subsequently,the chirped laser pulses are compressed down to 60 fs with 26.5 mJ energy,corresponding to a peak power of 0.44 TW. This high-energy,long-wavelength laser source is highly suitable for driving various nonlinear optical phenomena,such as high-order harmonic generation and high-flux coherent extreme ultraviolet/soft X-ray radiation.
文摘In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can generate high-intensity THz pulses(a)those with large-aperture dipoles and(b)those with interdigitated electrodes.We will first describe the principles of THz generation from PCAs.The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized.We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with widebandgap semiconductor substrates.Then,we will explain the evolution of LAPCA with interdigitated electrodes,which allows one to reduce the photoconductive gap size,and thus obtain higher bias fields while applying lower voltages.We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by ampli-fied lasers.Finally,we will discuss the future perspectives of THz pulse generation using LAPCAs.
基金The authors acknowledge support of the technology and cleanroom facility FIRST of ETH Zurich for advanced micro-and nanotechnologyThis work was financed by the Swiss Confederation Program Nano-Tera.ch,which was scientifically evaluated by the Swiss National Science Foundation(SNSF).
文摘The performance of ultrafast semiconductor disk lasers has rapidly advanced in recent decades.The strong interest from industry for inexpensive,compact,and reliable ultrafast laser sources in the picosecond and femtosecond domains has driven this technology toward commercial products.Frequency metrology and biomedical applications would benefit from sub-200-femtosecond pulse durations with peak powers in the kilowatt range.The aim of this review is to briefly describe the market potential and give an overview of the current status of mode-locked semiconductor disk lasers.Particular focus is placed on the ongoing efforts to achieve shorter pulses with higher peak powers.
基金National Natural Science Foundation of China(NSFC)(11574079,61475102,61775056)Natural Science Foundation of Hunan Province(2017JJ1013)Ministry of Education of the People’s Republic of China(MOE)(6141A02033404)
文摘Ultrafast fiber lasers are in great demand for various applications, such as optical communication, spectroscopy,biomedical diagnosis, and industrial fabrication. Here, we report the highly stable femtosecond pulse generation from a MXene mode-locked fiber laser. We have prepared the high-quality Ti_3C_2 T_x nanosheets via the etching method, and characterized their ultrafast dynamics and broadband nonlinear optical responses. The obvious intensity-and wavelength-dependent nonlinear responses have been observed and investigated. In addition, a highly stable femtosecond fiber laser with signal-to-noise ratio up to 70.7 dB and central wavelength of 1567.3 nm has been delivered. The study may provide some valuable design guidelines for the development of ultrafast, broadband nonlinear optical modulators, and open new avenues toward advanced photonic devices based on MXenes.
