A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conv...A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.展开更多
We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating d...We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating design.In a five-pass configuration,the amplifier yields a 42.3 W linearly polarized 1319 nm output at repetition rate of 1 kHz with pulse duration of 75μs and beam quality factors of M^(2)_(x)=1.13 and M^(2)_(y)=2.16 in the orthogonal directions.The fluctuation of the amplifier output power is measured to be±0.6%.Furthermore,a computational model of QCW pulse amplification is employed to examine the amplification process.展开更多
We demonstrate a high-power single-frequency diode-side pumped Nd:YAG laser at 1064 nm.A bow-tie ring cavity configuration comprising two plane and two curved mirrors with two-rod birefringence compensation is employe...We demonstrate a high-power single-frequency diode-side pumped Nd:YAG laser at 1064 nm.A bow-tie ring cavity configuration comprising two plane and two curved mirrors with two-rod birefringence compensation is employed.The influence of length Lx between two curved mirrors on output power and beam quality is investigated theoretically and experimentally while the separation of the flat mirrors is set to be 656 mm and the fold angle is 10°.When the pump powers are 358,343 and 329 W at 808 nm,the maximal output powers of 31.9,26 and 14.1 W are obtained with beam quality factors M2=1.41,1.12 and 1.20 for Lx=205,215 and 230 mm,respectively.展开更多
The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates wit...The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates with average output power of 2.1 W.A quantitative theoretical description agrees well with the experimental results.展开更多
The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the...The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the new(Ca,La)FeAs_(2)superconductor investigated by both band structure calculations and high resolution angle-resolved photoemission spectroscopy measurements.Band structure calculations indicate that there are four hole-like bands around the zone centerΓ(0,0)and two electron-like bands near the zone corner M(π,π)in CaFeAs_(2).In our angle-resolved photoemission measurements on(Ca0.9La0.1)FeAs_(2),we have observed three hole-like bands around theΓpoint and one electron-like Fermi surface near the M(π,π)point.These results provide important information to compare and contrast with the electronic structure of other iron-based compounds in understanding the superconductivity mechanism in the iron-based superconductors.展开更多
A 785 nm diode-side-pumped high-power high-pulse-repetition-frequency Q-switched 2 μm Tm:YAG laser system is reported.Under a pump power of 1300 W,a 171.4 W average output power is achieved at a pulse repetition freq...A 785 nm diode-side-pumped high-power high-pulse-repetition-frequency Q-switched 2 μm Tm:YAG laser system is reported.Under a pump power of 1300 W,a 171.4 W average output power is achieved at a pulse repetition frequency of 10 kHz.To our knowledge,this is the highest average output power for a diode-pumped all solid-state Q-switched 2 μm Tm:YAG laser.The laser output corresponds to an optical-to-optical conversion efficiency of 13.3% and a slope efficiency of 18.9%.展开更多
A special prism coupling technique with the KBe_(2)BO_(3)F_(2) crystal is adopted to produce deep ultraviolet light including the fourth harmonic from an Nd:YAG laser,for which a conversion efficiency as high as 10%ha...A special prism coupling technique with the KBe_(2)BO_(3)F_(2) crystal is adopted to produce deep ultraviolet light including the fourth harmonic from an Nd:YAG laser,for which a conversion efficiency as high as 10%has been obtained.展开更多
We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output p...We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output power of the fundamental wave at 1342nm from Nd:YVO_(4) was 2.3W with slope-efficiency of 43%.展开更多
We report a compact high power Tm,Ho：YAG laser nearly at room temperature. The laser-diode side-pumped Tm：YAG and Tm,Ho：YAG laser modules are operated in the same cavity. The laser yields 37.34 W of continuous wave...We report a compact high power Tm,Ho：YAG laser nearly at room temperature. The laser-diode side-pumped Tm：YAG and Tm,Ho：YAG laser modules are operated in the same cavity. The laser yields 37.34 W of continuous wave output power under the temperature of 6℃, corresponding to a maximum slope efficiency of 16.7% when the output power lies from 5.1 W to 27.0 W. This is the first report on the combined Tm：YAG and Tm,Ho：YAG lasers for obtaining high power 2.1 μm laser.展开更多
High resolution angle-resolved photoemission measurements are carried out to systematically investigate the effect of cleaving temperature on the electronic structures and Fermi surfaces of Sr2RuO4.Unlike previous rep...High resolution angle-resolved photoemission measurements are carried out to systematically investigate the effect of cleaving temperature on the electronic structures and Fermi surfaces of Sr2RuO4.Unlike previous reports,which found that a high cleaving temperature can suppress the surface Fermi surface,we find that the surface Fermi surface remains obvious and strong in Sr2RuO4 cleaved at high temperature,even at room temperature.This indicates that cleaving temperature is not a key effective factor in suppressing surface bands.On the other hand,the bulk bands can be enhanced in an aged surface of Sr2RuO4 that has been cleaved and held for a long time.We have also carried out laser ARPES measurements on Sr_(2)RuO_(4) by using a vacuum ultra-violet laser (photon energy at 6.994eV) and found an obvious enhancement of bulk bands even for samples cleaved at low temperature.This information is important for realizing an effective approach to manipulating and detecting the surface and bulk electronic structure of Sr2RuO4.In particular,the enhancement of bulk sensitivity,along with the super-high instrumental resolution of VUV laser ARPES,will be advantageous in investigating fine electronic structure and superconducting properties of Sr_(2)RuO_(4) in the future.展开更多
Tomographic imaging and three-dimensional reconstruction based on a high-gain picosecond optical parametric amplifier (OPA) is demonstrated. More than 40dB intensity amplification of the image is achieved from the hig...Tomographic imaging and three-dimensional reconstruction based on a high-gain picosecond optical parametric amplifier (OPA) is demonstrated. More than 40dB intensity amplification of the image is achieved from the high-gain OPA.The images of various longitudinal positions of the target are extracted by the gated nature of the OPA,then a three-dimensional (3-D) surface topography of the target is reconstructed.The gated and high-gain property of the OPA allows tomographic optical imaging together with 3-D profile reconstruction of the target in turbid media.展开更多
We report on a polarization-adjustable picosecond deep-ultraviolet (DUV) laser at 177.3 nm.The DUV laser was produced by second harmonic generation from a mode-locked laser at 355 nm in nonlinear optical crystal KBBF....We report on a polarization-adjustable picosecond deep-ultraviolet (DUV) laser at 177.3 nm.The DUV laser was produced by second harmonic generation from a mode-locked laser at 355 nm in nonlinear optical crystal KBBF.The laser delivered a maximum average output power of 1.1 m W at 177.3 nm.The polarization of the 177.3nm beam was adjusted with linear and circular polarization by means of λ/4 and λ/2 wave plates.To the best of our knowledge,the laser has been employed as the circularly polarized and linearly polarized DUV light source for a spin- and angle-resolved photoemission spectroscopy with high resolution for the first time.展开更多
High quality single crystals of heavy Fermion CeCoIn_(5) superconductor have been grown by flux method with a typical size of(1-2)×(1-2)×(~0.1)mm^(3).The single crystals are characterized by structural analy...High quality single crystals of heavy Fermion CeCoIn_(5) superconductor have been grown by flux method with a typical size of(1-2)×(1-2)×(~0.1)mm^(3).The single crystals are characterized by structural analysis from x-ray diffraction and Laue diffraction,as well as compositional analysis.Magnetic and electrical measurements on the single crystals show a sharp superconducting transition with a transition temperature at T_(c,onset)~2.3 K and a transition width of~0.15 K.The resistivity of the CeCoIn_(5) crystal exhibits a hump at~45 K,which is typical of a heavy Fermion system.High resolution angle-resolved photoemission spectroscopy(ARPES)measurements of CeCoIn_(5) reveal clear Fermi surface sheets that are consistent with the band structure calculations when assuming itinerant Ce 4f electrons at low temperature.This work provides important information on the electronic structure of heavy Fermion CeCoIn_(5) superconductor.It also lays a foundation for further studies on the physical properties and superconducting mechanism of the heavy Fermion superconductors.展开更多
A diode-side-pumped Nd:YAG ceramic slab laser with a high power output is presented.An average power of 526 W is achieved at 1064 nm with a repetition rate of 120 Hz and a pulse width of 180µs from a 93mm×52...A diode-side-pumped Nd:YAG ceramic slab laser with a high power output is presented.An average power of 526 W is achieved at 1064 nm with a repetition rate of 120 Hz and a pulse width of 180µs from a 93mm×52mm×8mm ceramic slab at a pump power of 1928 W,corresponding to an optical-to-optical efficiency of 27.3%.展开更多
Simultaneous red and blue light generation in an LiTaO_(3) crystal with a double grating structure is first reported.The double grating consists of two separate domain reversal sequences(superlattices)in series and is...Simultaneous red and blue light generation in an LiTaO_(3) crystal with a double grating structure is first reported.The double grating consists of two separate domain reversal sequences(superlattices)in series and is fabricated by field poling technique at room temperature.Using a picosecond 532 nm laser as a pump source,the red light at 631 nm and blue light at 460 nm are generated at the same time.A possible application of the superlattice crystal is presented.展开更多
With a type-I noncritically phase-matched LiB_(3)O_(5) crystal as the intracavity frequency doubler in a diode pumped Nd:YVO_(4) laser,440mW of 671 nm light was obtained at 5.5W of incident pump power,the optical-opti...With a type-I noncritically phase-matched LiB_(3)O_(5) crystal as the intracavity frequency doubler in a diode pumped Nd:YVO_(4) laser,440mW of 671 nm light was obtained at 5.5W of incident pump power,the optical-optical conversion efficiency being 8.0%.展开更多
We report a new type of optical parametric oscillator(OPO)cavity,i.e.,a compound cavity OPO.Both the numerical simulation and experimental results show that this type of cavity is superior,in that its threshold is low...We report a new type of optical parametric oscillator(OPO)cavity,i.e.,a compound cavity OPO.Both the numerical simulation and experimental results show that this type of cavity is superior,in that its threshold is lower than that of a simple narrow-band cavity with dispersive elements,and its external efficiency is increased while its narrow linewidth remains nearly the same across the tunable range of the nonlinear crystals used.展开更多
基金Supported by the National Advanced Materials Committee of the"863 Program"under Grant No.970311043。
文摘A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.
基金Supported by the National Basic Research Program of China under Grant No 2010CB630706the National High-Technology Research and Development Program under Grant No 2011AA030202the National Natural Science Foundation of China under Grant No 50990304.
文摘We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating design.In a five-pass configuration,the amplifier yields a 42.3 W linearly polarized 1319 nm output at repetition rate of 1 kHz with pulse duration of 75μs and beam quality factors of M^(2)_(x)=1.13 and M^(2)_(y)=2.16 in the orthogonal directions.The fluctuation of the amplifier output power is measured to be±0.6%.Furthermore,a computational model of QCW pulse amplification is employed to examine the amplification process.
基金by the National Basic Research Program of China under Grant No 2010CB630706the National High Technology Research and Development Program+1 种基金the National Natural Science Foundation of Chinathe Knowledge Innovation Program of Chinese Academy of Sciences。
文摘We demonstrate a high-power single-frequency diode-side pumped Nd:YAG laser at 1064 nm.A bow-tie ring cavity configuration comprising two plane and two curved mirrors with two-rod birefringence compensation is employed.The influence of length Lx between two curved mirrors on output power and beam quality is investigated theoretically and experimentally while the separation of the flat mirrors is set to be 656 mm and the fold angle is 10°.When the pump powers are 358,343 and 329 W at 808 nm,the maximal output powers of 31.9,26 and 14.1 W are obtained with beam quality factors M2=1.41,1.12 and 1.20 for Lx=205,215 and 230 mm,respectively.
基金Supported by the 863 Program of National Advanced Materials Committee
文摘The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is reported.Optimum coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates with average output power of 2.1 W.A quantitative theoretical description agrees well with the experimental results.
基金Supported by the National Natural Science Foundation of China under Grant No 10734120the National Basic Research Program of China under Grant Nos 2011CB921703 and 2011CB605903.
文摘The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the new(Ca,La)FeAs_(2)superconductor investigated by both band structure calculations and high resolution angle-resolved photoemission spectroscopy measurements.Band structure calculations indicate that there are four hole-like bands around the zone centerΓ(0,0)and two electron-like bands near the zone corner M(π,π)in CaFeAs_(2).In our angle-resolved photoemission measurements on(Ca0.9La0.1)FeAs_(2),we have observed three hole-like bands around theΓpoint and one electron-like Fermi surface near the M(π,π)point.These results provide important information to compare and contrast with the electronic structure of other iron-based compounds in understanding the superconductivity mechanism in the iron-based superconductors.
基金Supported by the National High-Technology Research and Development Program of Chinathe National Basic Research Pro-gram of China,the National Natural Science Foundation of Chinathe Knowledge Innovation Program of Chinese Academy of Sciences.
文摘A 785 nm diode-side-pumped high-power high-pulse-repetition-frequency Q-switched 2 μm Tm:YAG laser system is reported.Under a pump power of 1300 W,a 171.4 W average output power is achieved at a pulse repetition frequency of 10 kHz.To our knowledge,this is the highest average output power for a diode-pumped all solid-state Q-switched 2 μm Tm:YAG laser.The laser output corresponds to an optical-to-optical conversion efficiency of 13.3% and a slope efficiency of 18.9%.
文摘A special prism coupling technique with the KBe_(2)BO_(3)F_(2) crystal is adopted to produce deep ultraviolet light including the fourth harmonic from an Nd:YAG laser,for which a conversion efficiency as high as 10%has been obtained.
基金Supported by the National Advanced Materials Commit tee of the“863 Program”(863-715-001-00).
文摘We have demonstrated a diode-pumped Nd:YVO4 laser that produced 273mW cw output at 671 nm by using KTP intracavity doubling.The optical-optical efficiency of the all-solid-state red laser was 5.1%.The maximum output power of the fundamental wave at 1342nm from Nd:YVO_(4) was 2.3W with slope-efficiency of 43%.
文摘We report a compact high power Tm,Ho：YAG laser nearly at room temperature. The laser-diode side-pumped Tm：YAG and Tm,Ho：YAG laser modules are operated in the same cavity. The laser yields 37.34 W of continuous wave output power under the temperature of 6℃, corresponding to a maximum slope efficiency of 16.7% when the output power lies from 5.1 W to 27.0 W. This is the first report on the combined Tm：YAG and Tm,Ho：YAG lasers for obtaining high power 2.1 μm laser.
基金Support by the National Natural Science Foundation of China under Grant Nos 10734120 and 91021006the National Basic Research Program of China under Grant Nos 2011CB921703 and 2011CB605903.
文摘High resolution angle-resolved photoemission measurements are carried out to systematically investigate the effect of cleaving temperature on the electronic structures and Fermi surfaces of Sr2RuO4.Unlike previous reports,which found that a high cleaving temperature can suppress the surface Fermi surface,we find that the surface Fermi surface remains obvious and strong in Sr2RuO4 cleaved at high temperature,even at room temperature.This indicates that cleaving temperature is not a key effective factor in suppressing surface bands.On the other hand,the bulk bands can be enhanced in an aged surface of Sr2RuO4 that has been cleaved and held for a long time.We have also carried out laser ARPES measurements on Sr_(2)RuO_(4) by using a vacuum ultra-violet laser (photon energy at 6.994eV) and found an obvious enhancement of bulk bands even for samples cleaved at low temperature.This information is important for realizing an effective approach to manipulating and detecting the surface and bulk electronic structure of Sr2RuO4.In particular,the enhancement of bulk sensitivity,along with the super-high instrumental resolution of VUV laser ARPES,will be advantageous in investigating fine electronic structure and superconducting properties of Sr_(2)RuO_(4) in the future.
文摘Tomographic imaging and three-dimensional reconstruction based on a high-gain picosecond optical parametric amplifier (OPA) is demonstrated. More than 40dB intensity amplification of the image is achieved from the high-gain OPA.The images of various longitudinal positions of the target are extracted by the gated nature of the OPA,then a three-dimensional (3-D) surface topography of the target is reconstructed.The gated and high-gain property of the OPA allows tomographic optical imaging together with 3-D profile reconstruction of the target in turbid media.
基金Supported by the National Basic Research Program of China under Grant No 2010CB630706the National High-Technology Research and Development Program of Chinathe National Natural Science Foundation of China,and the Knowledge Innovation Program of Chinese Academy of Sciences.
文摘We report on a polarization-adjustable picosecond deep-ultraviolet (DUV) laser at 177.3 nm.The DUV laser was produced by second harmonic generation from a mode-locked laser at 355 nm in nonlinear optical crystal KBBF.The laser delivered a maximum average output power of 1.1 m W at 177.3 nm.The polarization of the 177.3nm beam was adjusted with linear and circular polarization by means of λ/4 and λ/2 wave plates.To the best of our knowledge,the laser has been employed as the circularly polarized and linearly polarized DUV light source for a spin- and angle-resolved photoemission spectroscopy with high resolution for the first time.
基金Supported by the National Natural Science Foundation of China under Grant No 10734120the National Basic Research Prograom of China under Grant No 2011CB921703.
文摘High quality single crystals of heavy Fermion CeCoIn_(5) superconductor have been grown by flux method with a typical size of(1-2)×(1-2)×(~0.1)mm^(3).The single crystals are characterized by structural analysis from x-ray diffraction and Laue diffraction,as well as compositional analysis.Magnetic and electrical measurements on the single crystals show a sharp superconducting transition with a transition temperature at T_(c,onset)~2.3 K and a transition width of~0.15 K.The resistivity of the CeCoIn_(5) crystal exhibits a hump at~45 K,which is typical of a heavy Fermion system.High resolution angle-resolved photoemission spectroscopy(ARPES)measurements of CeCoIn_(5) reveal clear Fermi surface sheets that are consistent with the band structure calculations when assuming itinerant Ce 4f electrons at low temperature.This work provides important information on the electronic structure of heavy Fermion CeCoIn_(5) superconductor.It also lays a foundation for further studies on the physical properties and superconducting mechanism of the heavy Fermion superconductors.
基金by the Major Program of the National Natural Science Foundation of China under Grant No 50990304the Natural Science Foundation of Shanghai under Grant No 09ZR1435600.
文摘A diode-side-pumped Nd:YAG ceramic slab laser with a high power output is presented.An average power of 526 W is achieved at 1064 nm with a repetition rate of 120 Hz and a pulse width of 180µs from a 93mm×52mm×8mm ceramic slab at a pump power of 1928 W,corresponding to an optical-to-optical efficiency of 27.3%.
基金Supported by the State Key Program from the National Science and Technology Commission of Chinathe National Advanced Material Commit tee of China,and the National Natural Science Foundation of China under Grant No.69938010.S.N.Zhu is also grateful for the support from a mono-grant RFPP.
文摘Simultaneous red and blue light generation in an LiTaO_(3) crystal with a double grating structure is first reported.The double grating consists of two separate domain reversal sequences(superlattices)in series and is fabricated by field poling technique at room temperature.Using a picosecond 532 nm laser as a pump source,the red light at 631 nm and blue light at 460 nm are generated at the same time.A possible application of the superlattice crystal is presented.
基金Supported by the National Advanced Materials Commit tee of the"863 Program"under Grant No.863-715-001-00.
文摘With a type-I noncritically phase-matched LiB_(3)O_(5) crystal as the intracavity frequency doubler in a diode pumped Nd:YVO_(4) laser,440mW of 671 nm light was obtained at 5.5W of incident pump power,the optical-optical conversion efficiency being 8.0%.
基金Supported by the National Natural Science Foundation of China under Grant No.69678005the“863”Program(715-001-0020)of China。
文摘We report a new type of optical parametric oscillator(OPO)cavity,i.e.,a compound cavity OPO.Both the numerical simulation and experimental results show that this type of cavity is superior,in that its threshold is lower than that of a simple narrow-band cavity with dispersive elements,and its external efficiency is increased while its narrow linewidth remains nearly the same across the tunable range of the nonlinear crystals used.
