This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source...This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700 nm to 756.5 nm, another from 830 nm to 900mn have been demonstrated. With a pump power of 23 W at 532 nm, a repetition rate of 7 kHz and a pulse width of 47.6 ns, an output power of 5.1 W at 744.8 nm and 860.9 nm with a pulse width of 13.2 ns and a line width of 3 nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2%.展开更多
A high-pulse-energy high-beam-quality tunable Ti：sapphire laser pumped by a frequency-doubled Nd：YAG laser is demonstrated. Using a fused-silica prism as the dispersion element, a tuning range of 740-855 nm is obtai...A high-pulse-energy high-beam-quality tunable Ti：sapphire laser pumped by a frequency-doubled Nd：YAG laser is demonstrated. Using a fused-silica prism as the dispersion element, a tuning range of 740-855 nm is obtained. At an incident pump energy of 774mJ, the maximum output energy of 104mJ at 790nm with a pulse width of 100μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, it is the highest pulse energy at 790 nm with pulse width of hundred micro-seconds for an all-solid-state laser. The linewidth of output is 0.5 nm, and the beam quality factor M2 is 1.16. The high-pulse-energy high-beam-quality tunable Ti：sapphire laser in the range of 740-855 nm can be used to establish a more accurate and consistent absolute scale of second-order optical-nonlinear coefficients for KBe2BO3F2 measured in a wider wavelength range and to assess Miller＇s rule quantitatively.展开更多
We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump....We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.展开更多
A Kerr-lens mode-locked Ti：sapphire laser operating in a non-soliton regime is demonstrated. Dispersive wave generation is observed as a result of third order dispersion in the vicinity of zero dispersion. The charac...A Kerr-lens mode-locked Ti：sapphire laser operating in a non-soliton regime is demonstrated. Dispersive wave generation is observed as a result of third order dispersion in the vicinity of zero dispersion. The characteristics of the Ti：sapphire l^ser operating in a positive dispersion regime are presented, where the oscillator directly generates pulses with duration continuously tunable from 0.37 ps to 2.11 ps, and 36 fs pulses are achieved atter extracavity compression. The oscillation is numerically simulated with an extended nonlinear Schr6dinger equation, and the simulation results are in good agreement with the experimental results.展开更多
We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses a...We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses as short as 17 fs are generated at a central wavelength of 736 nm with an average output power of 31 mW.The maximum output power is 46.8 mW at a central wavelength of 797 nm with a pulse duration of 46 fs.展开更多
We demonstrate a 100-TW-class femtosecond Ti:sapphire laser running at a repetition rate of 0.1Hz based on a 20TW/10 Hz laser facility (XL-Ⅱ).Pumping the new stage amplifier with a 25J green Nd:glass laser,we success...We demonstrate a 100-TW-class femtosecond Ti:sapphire laser running at a repetition rate of 0.1Hz based on a 20TW/10 Hz laser facility (XL-Ⅱ).Pumping the new stage amplifier with a 25J green Nd:glass laser,we successfully improve the laser energy to 3.4J with duration of 29 fs,corresponding to a peak power of 11 7 TW.展开更多
We report a long-term frequency-stabilized optical frequency comb at 530–1100 nm based on a turnkey Ti:sapphire modelocked laser.With the help of a digital controller,turnkey operation is realized for the Ti:sapphire...We report a long-term frequency-stabilized optical frequency comb at 530–1100 nm based on a turnkey Ti:sapphire modelocked laser.With the help of a digital controller,turnkey operation is realized for the Ti:sapphire mode-locked laser.Under optimized design of the laser cavity,the laser can be mode-locked over a month,limited by the observation time.The combination of a fast piezo and a slow one inside the Ti:sapphire mode-locked laser allows us to adjust the cavity length with moderate bandwidth and tuning range,enabling robust locking of the repetition rate(f_(r)) to a hydrogen maser.By combining a fast analog feedback to pump current and a slow digital feedback to an intracavity wedge and the pump power of the Ti:sapphire mode-locked laser,the carrier envelope offset frequency(f_(ceo)) of the comb is stabilized.We extend the continuous frequency-stabilized time of the Ti:sapphire optical frequency comb to five days.The residual jitters of f;and f;are 0.08 m Hz and 2.5 m Hz at 1 s averaging time,respectively,satisfying many applications demanding accuracy and short operation time for optical frequency combs.展开更多
A compact femtosecond Ti:sapphire laser resonator consisting of three chirped mirrors and one output coupler was designed. By accurately balancing the intra- cavity dispersions between Ti:sapphire crystal, air and chi...A compact femtosecond Ti:sapphire laser resonator consisting of three chirped mirrors and one output coupler was designed. By accurately balancing the intra- cavity dispersions between Ti:sapphire crystal, air and chirped mirrors, we directly generated the laser pulse shorter than 7 fs at the average power of 340 mW with 3.1 W pump. The repetition rate of the laser oscillator is 173 MHz at the centre wavelength of 791 nm, and the ultrabroaden spectrum covers from 600 nm to 1000 nm. To the best of our knowledge, this is the simplest laser resonator capable of generating sub-10 fs laser pulse.展开更多
An efficient chirped-pulse amplification, Ti:sapphire laser system, has been developed using mainly domestic components. The gain-narrowing effect has been significantly overcome by shaping spectrum of seeding pulses....An efficient chirped-pulse amplification, Ti:sapphire laser system, has been developed using mainly domestic components. The gain-narrowing effect has been significantly overcome by shaping spectrum of seeding pulses. With a novel aberration-free stretcher and two stage multi-pass amplifiers, pulses with duration of 25 fs and 36-mJ energy have been obtained at 10 Hz repetition rate, using only less than 290 mJ green Nd: YAG pump energy. This corresponds to a 1.4 TW peak power and 32% main amplification efficiency. The energy stability of the laser systems is better than ± 3% .展开更多
Residual infrared absorption is a key problem affecting the laser emission efficiency of Ti:sapphire crystal.In this paper,the origin of residual infrared absorption of Ti:sapphire crystal is systematically studied by...Residual infrared absorption is a key problem affecting the laser emission efficiency of Ti:sapphire crystal.In this paper,the origin of residual infrared absorption of Ti:sapphire crystal is systematically studied by using the first principles method.According to the contact conditions of O octahedron in the crystal structure of Al_(2)O_(3),four Ti^(3+)−Ti^(3+)ion pair models and three Ti^(4+)−Ti^(3+)ion pair models were defined and constructed.For what we believe is the first time,the near-infrared absorption spectra consistent with the experimental results were obtained in specific theoretical models.The electronic structures,absorption spectra,and charge distributions calculated show that the line-contact Ti^(3+)−Ti^(3+)ion pair with antiferromagnetic coupling and the facecontact Ti^(4+)−Ti^(3+)ion pair are two main contributors to the residual infrared absorption of Ti:sapphire,while some other ion pair models provide a basis to explain more complex residual infrared absorption.展开更多
Emerging multi-PW-class lasers and their envisioned laser-plasma interaction applications in unprecedented intensity regimes set a very demanding frame for the precise understanding of the finest properties of these s...Emerging multi-PW-class lasers and their envisioned laser-plasma interaction applications in unprecedented intensity regimes set a very demanding frame for the precise understanding of the finest properties of these systems.In this work we present a synthesis of simulation studies on a series of less known or even completely disregarded spatiotemporal effects that could potentially impact greatly the performances of high-intensity lasers.展开更多
We demonstrate a harmonic mode-locked ytterbium-doped fibre ring laser, which consists of a polarization-sensitive isolator, two polarization controllers, two 976nm laser diodes as the pump source and a two-segment yt...We demonstrate a harmonic mode-locked ytterbium-doped fibre ring laser, which consists of a polarization-sensitive isolator, two polarization controllers, two 976nm laser diodes as the pump source and a two-segment ytterbium-doped fibre. Utilizing an additive pulse mode-locked technique based on nonlinear polarization evolution, the ytterbium-doped fibre laser can operate in mode-locked state by adjusting the position of polarization controllers. The cavity fundamental repetition rate is 23.78 MHz. We also observe the second- and third-harmonic mode locking in the normal dispersion region, and their repetition rates are 47.66 MHz and 71.56 MHz, respectively. Over-driving of the saturable absorber in the harmonic mode-locking pulse is analysed and discussed in detail.展开更多
We systematically study the optimization of highly efficient terahertz（THz） generation in lithium niobate（LN）crystal pumped by 800 nm laser pulses with 30 fs pulse duration. At room temperature, we obtain a record...We systematically study the optimization of highly efficient terahertz（THz） generation in lithium niobate（LN）crystal pumped by 800 nm laser pulses with 30 fs pulse duration. At room temperature, we obtain a record optical-to-THz energy conversion efficiency of 0.43% by chirping the pump laser pulses. Our method provides a new technique for producing millijoule THz radiation in LN via optical rectification driven by joule-level Ti：sapphire laser systems, which deliver sub-50-fs pulse durations.展开更多
A great deal of progress has been made in self-mode-locked Ti: sapphire laser since itwas invented in 1991. It has already found wide uses owing to its broad spectrum abilityto generate short pulses, high output power...A great deal of progress has been made in self-mode-locked Ti: sapphire laser since itwas invented in 1991. It has already found wide uses owing to its broad spectrum abilityto generate short pulses, high output power, simple setup and good stabilities. Recentlypulses as short as 8.5 fs have been generated by a laser of this kind. By improving com-展开更多
基金Project supported in part by the National Natural Science Foundation of China （Grant Nos 10474071, 60637010, 60671036 and 60278001） and Tianjin Applied Fundamental Research Project, China （07JCZDJC05900）.
文摘This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700 nm to 756.5 nm, another from 830 nm to 900mn have been demonstrated. With a pump power of 23 W at 532 nm, a repetition rate of 7 kHz and a pulse width of 47.6 ns, an output power of 5.1 W at 744.8 nm and 860.9 nm with a pulse width of 13.2 ns and a line width of 3 nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2%.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61275157 and 61475040the National Key Scientific Instrument and Equipment Development,Project under Grant No 2012YQ120048+1 种基金the National Development Project for Major Scientific Research Facility under Grant No ZDYZ2012-2the National Key Research and Development Program of China under Grant No 2016YFB0402003
文摘A high-pulse-energy high-beam-quality tunable Ti：sapphire laser pumped by a frequency-doubled Nd：YAG laser is demonstrated. Using a fused-silica prism as the dispersion element, a tuning range of 740-855 nm is obtained. At an incident pump energy of 774mJ, the maximum output energy of 104mJ at 790nm with a pulse width of 100μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, it is the highest pulse energy at 790 nm with pulse width of hundred micro-seconds for an all-solid-state laser. The linewidth of output is 0.5 nm, and the beam quality factor M2 is 1.16. The high-pulse-energy high-beam-quality tunable Ti：sapphire laser in the range of 740-855 nm can be used to establish a more accurate and consistent absolute scale of second-order optical-nonlinear coefficients for KBe2BO3F2 measured in a wider wavelength range and to assess Miller＇s rule quantitatively.
基金Supported by the National Natural Science Foundation of China under Grant No 61735011the Natural Science Foundation of Hebei Province under Grant Nos F2016203389 and F2018105036+2 种基金the Science and Technology Research Project of College and University in Hebei Province under Grant No BJ2017108the Open Subject of Jiangsu Key Laboratory of Meteorological Observation and Information Processing under Grant No KDXS1107the Science and Technology Project of Tangshan City under Grant No 17130257a
文摘We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.
基金Project supported by the National Basic Research Program of China (Grant No. 2006CB806002)the National High Technology Research and Development Program of China (Grant No. 2007AA03Z447)+3 种基金National Natural Science Foundation of China (Grant Nos. 60678012 and 60838004)the Foundation for Key Program of Ministry of Education, China (Grant No. 108032)FANEDD(Grant No. 2007B34)NCET (Grant No. NCET-07-0597)
文摘A Kerr-lens mode-locked Ti：sapphire laser operating in a non-soliton regime is demonstrated. Dispersive wave generation is observed as a result of third order dispersion in the vicinity of zero dispersion. The characteristics of the Ti：sapphire l^ser operating in a positive dispersion regime are presented, where the oscillator directly generates pulses with duration continuously tunable from 0.37 ps to 2.11 ps, and 36 fs pulses are achieved atter extracavity compression. The oscillation is numerically simulated with an extended nonlinear Schr6dinger equation, and the simulation results are in good agreement with the experimental results.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFB0402105)
文摘We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses as short as 17 fs are generated at a central wavelength of 736 nm with an average output power of 31 mW.The maximum output power is 46.8 mW at a central wavelength of 797 nm with a pulse duration of 46 fs.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11074298,91126008,10804128 and 10925421the National Basic Research Program of China under Grant No 2007CB815104the Instrument Developing Project of Chinese Academy of Sciences under Grant No 2010004.
文摘We demonstrate a 100-TW-class femtosecond Ti:sapphire laser running at a repetition rate of 0.1Hz based on a 20TW/10 Hz laser facility (XL-Ⅱ).Pumping the new stage amplifier with a 25J green Nd:glass laser,we successfully improve the laser energy to 3.4J with duration of 29 fs,corresponding to a peak power of 11 7 TW.
基金supported by the National Key R&D Program of China(No.2017YFA0304403)the National Natural Science Foundation of China(Nos.11927810,11822402,and11804094)。
文摘We report a long-term frequency-stabilized optical frequency comb at 530–1100 nm based on a turnkey Ti:sapphire modelocked laser.With the help of a digital controller,turnkey operation is realized for the Ti:sapphire mode-locked laser.Under optimized design of the laser cavity,the laser can be mode-locked over a month,limited by the observation time.The combination of a fast piezo and a slow one inside the Ti:sapphire mode-locked laser allows us to adjust the cavity length with moderate bandwidth and tuning range,enabling robust locking of the repetition rate(f_(r)) to a hydrogen maser.By combining a fast analog feedback to pump current and a slow digital feedback to an intracavity wedge and the pump power of the Ti:sapphire mode-locked laser,the carrier envelope offset frequency(f_(ceo)) of the comb is stabilized.We extend the continuous frequency-stabilized time of the Ti:sapphire optical frequency comb to five days.The residual jitters of f;and f;are 0.08 m Hz and 2.5 m Hz at 1 s averaging time,respectively,satisfying many applications demanding accuracy and short operation time for optical frequency combs.
基金Supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 60490280, 10227401, 60225005 and 60321003)
文摘A compact femtosecond Ti:sapphire laser resonator consisting of three chirped mirrors and one output coupler was designed. By accurately balancing the intra- cavity dispersions between Ti:sapphire crystal, air and chirped mirrors, we directly generated the laser pulse shorter than 7 fs at the average power of 340 mW with 3.1 W pump. The repetition rate of the laser oscillator is 173 MHz at the centre wavelength of 791 nm, and the ultrabroaden spectrum covers from 600 nm to 1000 nm. To the best of our knowledge, this is the simplest laser resonator capable of generating sub-10 fs laser pulse.
文摘An efficient chirped-pulse amplification, Ti:sapphire laser system, has been developed using mainly domestic components. The gain-narrowing effect has been significantly overcome by shaping spectrum of seeding pulses. With a novel aberration-free stretcher and two stage multi-pass amplifiers, pulses with duration of 25 fs and 36-mJ energy have been obtained at 10 Hz repetition rate, using only less than 290 mJ green Nd: YAG pump energy. This corresponds to a 1.4 TW peak power and 32% main amplification efficiency. The energy stability of the laser systems is better than ± 3% .
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB1603)National Key Research and Development Program of China(2016YFB0402105)+1 种基金National Natural Science Foundation of China(51872307)Shanghai Technical Trade Measures Response Special Project(19TBT017).
文摘Residual infrared absorption is a key problem affecting the laser emission efficiency of Ti:sapphire crystal.In this paper,the origin of residual infrared absorption of Ti:sapphire crystal is systematically studied by using the first principles method.According to the contact conditions of O octahedron in the crystal structure of Al_(2)O_(3),four Ti^(3+)−Ti^(3+)ion pair models and three Ti^(4+)−Ti^(3+)ion pair models were defined and constructed.For what we believe is the first time,the near-infrared absorption spectra consistent with the experimental results were obtained in specific theoretical models.The electronic structures,absorption spectra,and charge distributions calculated show that the line-contact Ti^(3+)−Ti^(3+)ion pair with antiferromagnetic coupling and the facecontact Ti^(4+)−Ti^(3+)ion pair are two main contributors to the residual infrared absorption of Ti:sapphire,while some other ion pair models provide a basis to explain more complex residual infrared absorption.
文摘Emerging multi-PW-class lasers and their envisioned laser-plasma interaction applications in unprecedented intensity regimes set a very demanding frame for the precise understanding of the finest properties of these systems.In this work we present a synthesis of simulation studies on a series of less known or even completely disregarded spatiotemporal effects that could potentially impact greatly the performances of high-intensity lasers.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60577019 and 60137010.
文摘We demonstrate a harmonic mode-locked ytterbium-doped fibre ring laser, which consists of a polarization-sensitive isolator, two polarization controllers, two 976nm laser diodes as the pump source and a two-segment ytterbium-doped fibre. Utilizing an additive pulse mode-locked technique based on nonlinear polarization evolution, the ytterbium-doped fibre laser can operate in mode-locked state by adjusting the position of polarization controllers. The cavity fundamental repetition rate is 23.78 MHz. We also observe the second- and third-harmonic mode locking in the normal dispersion region, and their repetition rates are 47.66 MHz and 71.56 MHz, respectively. Over-driving of the saturable absorber in the harmonic mode-locking pulse is analysed and discussed in detail.
基金supported by the National Basic Research Program of China(No.2013CBA01501)the National Natural Science Foundation of China(No.11520101003)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB16010200 and XDB07030300)the "Zhuoyue" Program of Beihang University(No.GZ216S1711)
文摘We systematically study the optimization of highly efficient terahertz（THz） generation in lithium niobate（LN）crystal pumped by 800 nm laser pulses with 30 fs pulse duration. At room temperature, we obtain a record optical-to-THz energy conversion efficiency of 0.43% by chirping the pump laser pulses. Our method provides a new technique for producing millijoule THz radiation in LN via optical rectification driven by joule-level Ti：sapphire laser systems, which deliver sub-50-fs pulse durations.
文摘A great deal of progress has been made in self-mode-locked Ti: sapphire laser since itwas invented in 1991. It has already found wide uses owing to its broad spectrum abilityto generate short pulses, high output power, simple setup and good stabilities. Recentlypulses as short as 8.5 fs have been generated by a laser of this kind. By improving com-
