We demonstrate a widely tunable near-infrared source from 767 nm to 874 nm generated by the intracavity second harmonic generation （SHG） in an optical parametric oscillator pumped by a Yb：LYSO solid-state laser. Th...We demonstrate a widely tunable near-infrared source from 767 nm to 874 nm generated by the intracavity second harmonic generation （SHG） in an optical parametric oscillator pumped by a Yb：LYSO solid-state laser. The home-made Yb：LYSO oscillator centered at 1035 nm delivers an average power of 2 W and a pulse duration as short as 351 fs. TWo MgO doped periodically poled lithium niobates （MgO：PPLN） with grating periods of 28.5-31.5 μm in steps of 0.5 μm and 19.5-21.3μm in steps of 0.2 μm are used for the OPO and intracavity SHG, respectively. The maximum average output power of 180 mW at 798 nm was obtained and the output pulses have pulse duration of 313 fs at 792 nm if a sech2-pulse shape was assumed. In addition, tunable signal femtosecond pulses from 1428 nm to 1763 nm are also realized with the maximum average power of 355 mW at 1628 nm.展开更多
Positron Emission Tomography （PET） using time-of-flight information, which can greatly improve the quality of the reconstructed image, has recently become an exciting topic. In this work, 3.2 mm×3.2 min×25...Positron Emission Tomography （PET） using time-of-flight information, which can greatly improve the quality of the reconstructed image, has recently become an exciting topic. In this work, 3.2 mm×3.2 min×25 mm finger-like LYSO crystals were used to make a 5×5 array, coupled to the Hamamatsu H8500 photomultiplier tube （PMT） as a detector. A fast leading-edge discriminator was designed for the LYSO-H8500 detector. Average coinci- dence time resolution FWHM of 330 ps was obtained for the LYSO detector with a reference BaF2 detector, whose time resolution for 511 keV γ-rays was FWHM 150 ps. Time resolution FWHM of 294 ps was calculated for the LYSO detector, and coincidence time resolution of FHWM 415 ps can be expected for two identical LYSO detectors.展开更多
The high energy cosmic-radiation detection(HERD)facility is a space mission designed for detecting cosmic ray(CR)electrons,γ-rays up to tens of TeV and CR nuclei from proton to iron up to several PeV.The main instrum...The high energy cosmic-radiation detection(HERD)facility is a space mission designed for detecting cosmic ray(CR)electrons,γ-rays up to tens of TeV and CR nuclei from proton to iron up to several PeV.The main instrument of HERD is a 3-D imaging calorimeter(CALO)composed of nearly ten thousand lutetium yttrium orthosilicate(LYSO,with cerium doping)crystal cubes.A large dynamic range of single HERD CALO Cell(HCC)is necessary to achieve HERD’s PeV observation objectives,which means that the response of HCC should maintain a good linearity from minimum ionizing particle(MIP)calibration to PeV shower maximum.In order to study the linearity ofHCC over such a large energy range,a beam test has been implemented at the E2 and E3 beam lines of BEPC.High intensity pulsed electron beam provided by E2 line is used for producing high energy density within HCC;π^(+)/proton provided by E3 line are used forHCCcalibration.The results showthat no saturation effect occurs and the linearity ofHCCis better than 10%from 30 MeV(1MIP)to 1.1×10^(3) TeV(energy density is 93 TeV/cm^(3)),which can meet the requirement mentioned above.展开更多
By aiming the pump wavelength of the laser （Ndo.oo5Luo.4975Yo.4975）2SiO5 （Nd：LYSO） crystal 1 079 nm is obtained. The maximum output power corresponding to an optical conversion efficiency of diode to the absorpti...By aiming the pump wavelength of the laser （Ndo.oo5Luo.4975Yo.4975）2SiO5 （Nd：LYSO） crystal 1 079 nm is obtained. The maximum output power corresponding to an optical conversion efficiency of diode to the absorption peak at 811 an efficient dual-wavelength operation at 1 is 702 mW when the incident pump power is 27.7% and a slope efficiency of 37.0% of the 075 and 2.53W,展开更多
基金supported by the National Key Basic Research Program of China(Grant No.2013CB922402)the National Key Scientific Instruments Development Program of China(Grant No.2012YQ120047)+1 种基金the National Natural Science Foundation of China(Grant Nos.61205130 and 11174361)the Key Deployment Project of Chinese Academy of Sciences(Grant No.KJZD-EW-L11-03)
文摘We demonstrate a widely tunable near-infrared source from 767 nm to 874 nm generated by the intracavity second harmonic generation （SHG） in an optical parametric oscillator pumped by a Yb：LYSO solid-state laser. The home-made Yb：LYSO oscillator centered at 1035 nm delivers an average power of 2 W and a pulse duration as short as 351 fs. TWo MgO doped periodically poled lithium niobates （MgO：PPLN） with grating periods of 28.5-31.5 μm in steps of 0.5 μm and 19.5-21.3μm in steps of 0.2 μm are used for the OPO and intracavity SHG, respectively. The maximum average output power of 180 mW at 798 nm was obtained and the output pulses have pulse duration of 313 fs at 792 nm if a sech2-pulse shape was assumed. In addition, tunable signal femtosecond pulses from 1428 nm to 1763 nm are also realized with the maximum average power of 355 mW at 1628 nm.
基金Supported by National Natural Science Foundation of China(10775149,10805049)the Fundamental Research Funds for the Central Universities(2013NT10)
文摘Positron Emission Tomography （PET） using time-of-flight information, which can greatly improve the quality of the reconstructed image, has recently become an exciting topic. In this work, 3.2 mm×3.2 min×25 mm finger-like LYSO crystals were used to make a 5×5 array, coupled to the Hamamatsu H8500 photomultiplier tube （PMT） as a detector. A fast leading-edge discriminator was designed for the LYSO-H8500 detector. Average coinci- dence time resolution FWHM of 330 ps was obtained for the LYSO detector with a reference BaF2 detector, whose time resolution for 511 keV γ-rays was FWHM 150 ps. Time resolution FWHM of 294 ps was calculated for the LYSO detector, and coincidence time resolution of FHWM 415 ps can be expected for two identical LYSO detectors.
基金This research was supported by National Natural Science Foundation of China,Grant No.11327303,11473028 and 11675196International Science and Technology Cooperation Program of China,Grant No.2015DFA10140+3 种基金Interdisciplinary Innovation Team Project of Chinese Academy of Sciences(Research Team of The High Energy cosmic-Radiation Detection)Qianren start-up,Grant No.292012312D1117210Strategic Pioneer Program in Space Science,Chinese Academy of Sciences,Grant No.XDA04075600Youth Innovation Promotion Association of CAS,Grant No.2014009.The authors would like to thank Dr.Sun Jianchao,Dr.Zhang Xuan,Dr.Zhang Xiaofeng and Dr.Ning Zhe for their support.
文摘The high energy cosmic-radiation detection(HERD)facility is a space mission designed for detecting cosmic ray(CR)electrons,γ-rays up to tens of TeV and CR nuclei from proton to iron up to several PeV.The main instrument of HERD is a 3-D imaging calorimeter(CALO)composed of nearly ten thousand lutetium yttrium orthosilicate(LYSO,with cerium doping)crystal cubes.A large dynamic range of single HERD CALO Cell(HCC)is necessary to achieve HERD’s PeV observation objectives,which means that the response of HCC should maintain a good linearity from minimum ionizing particle(MIP)calibration to PeV shower maximum.In order to study the linearity ofHCC over such a large energy range,a beam test has been implemented at the E2 and E3 beam lines of BEPC.High intensity pulsed electron beam provided by E2 line is used for producing high energy density within HCC;π^(+)/proton provided by E3 line are used forHCCcalibration.The results showthat no saturation effect occurs and the linearity ofHCCis better than 10%from 30 MeV(1MIP)to 1.1×10^(3) TeV(energy density is 93 TeV/cm^(3)),which can meet the requirement mentioned above.
基金supported by the National Natural Science Foundation of China (Nos. 60978027, 60938001,and 61078054)the Natural Science Foundation of Shandong Province, China (Nos. 2009ZRB01907 and ZR2010EM001)+1 种基金the Program for New Century Excellent Talents in University (NCET-10-0526)the Independent Innovation Foundation of Shandong University (Nos. 2009TS129, 2010JC015, and 2010TS090)
文摘By aiming the pump wavelength of the laser （Ndo.oo5Luo.4975Yo.4975）2SiO5 （Nd：LYSO） crystal 1 079 nm is obtained. The maximum output power corresponding to an optical conversion efficiency of diode to the absorption peak at 811 an efficient dual-wavelength operation at 1 is 702 mW when the incident pump power is 27.7% and a slope efficiency of 37.0% of the 075 and 2.53W,
