We report a pulsed surface-emitted THz-wave parametric oscillator based on two MgO：LiNbO3 crystals pumped by a multi-longitudinal mode Q-switched Nd：YAG laser. Through varying the phase matching angle, the tunable T...We report a pulsed surface-emitted THz-wave parametric oscillator based on two MgO：LiNbO3 crystals pumped by a multi-longitudinal mode Q-switched Nd：YAG laser. Through varying the phase matching angle, the tunable THzwave output from 0.79 THz to 2.84 THz is realized. The maximum THz-wave output was 193.2 n J/pulse at 1.84 THz as the pump power density was 212.5 MW/cm2, corresponding to the energy conversion efficiency of 2.42Х10-6 and the photon conversion efficiency of about 0.037%. When the pump power density changed from 123 MW/cm^2 to 148 MW/cm^2 and 164 MW/cm^2, the maximum output of the THz-wave moved to the high frequency band. We give a reasonable explanation for this phenomenon.展开更多
Optical parametric chirped pulse amplification(OPCPA)shows great potential in producing ultrashort high-intensity pulses because of its large gain bandwidth.Quasi-parametric chirped pulse amplification(QPCPA)may furth...Optical parametric chirped pulse amplification(OPCPA)shows great potential in producing ultrashort high-intensity pulses because of its large gain bandwidth.Quasi-parametric chirped pulse amplification(QPCPA)may further extend the bandwidth.However,behavior of QPCPA at a limited pump intensity(e.g.,≤5 GW/cm^(2) in a nanosecond pumped QPCPA)has not yet been investigated fully.We discuss detailedly the ultra-broadband amplification and the noncollinear phasematching geometry in QPCPA,model and develop a novel noncollinear geometry in QPCPA,namely triple-wavelength phase-matching geometry,which provides two additional phase-matching points around the phase-matching point at the central wavelength.Our analysis demonstrates that the triple-wavelength phase-matching geometry can support stable,ultra-broadband amplification in QPCPA.The numerical simulation results show that ultrashort pulse with a pulse duration of 7.92 fs can be achieved in QPCPA when the pump intensity is limited to 5 GW/cm^(2),calculated using the nonlinear coefficient of YCa;O(BO;);.展开更多
A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching ...A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching method,low-threshold OPO operation could be obtained compared with the configuration of collinear phase matching,and the maximum optical–optical conversion efficiency of 11.8%was achieved at 500 nm wavelength when 0.4 m J pump pulse energy was applied.When the noncollinearity angle was preset at 1.6°,4.8°,and 6.3°,a continuously tuning output with a total spectral range of 220 nm was successfully obtained by adjusting the phase matching angle of the BBO crystal.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2007CB310403)the National Natural Science Foundation of China (Grant No. 60801017)the Research Fund for the Doctoral Program of Higher Education of China(Grant No. 20070420118)
文摘We report a pulsed surface-emitted THz-wave parametric oscillator based on two MgO：LiNbO3 crystals pumped by a multi-longitudinal mode Q-switched Nd：YAG laser. Through varying the phase matching angle, the tunable THzwave output from 0.79 THz to 2.84 THz is realized. The maximum THz-wave output was 193.2 n J/pulse at 1.84 THz as the pump power density was 212.5 MW/cm2, corresponding to the energy conversion efficiency of 2.42Х10-6 and the photon conversion efficiency of about 0.037%. When the pump power density changed from 123 MW/cm^2 to 148 MW/cm^2 and 164 MW/cm^2, the maximum output of the THz-wave moved to the high frequency band. We give a reasonable explanation for this phenomenon.
基金supported by the National Natural Science Foundation of China(Grant No.51832009)the Fundamental Research Funds for the Central Universities,China(Grant No.2019YJS209)。
文摘Optical parametric chirped pulse amplification(OPCPA)shows great potential in producing ultrashort high-intensity pulses because of its large gain bandwidth.Quasi-parametric chirped pulse amplification(QPCPA)may further extend the bandwidth.However,behavior of QPCPA at a limited pump intensity(e.g.,≤5 GW/cm^(2) in a nanosecond pumped QPCPA)has not yet been investigated fully.We discuss detailedly the ultra-broadband amplification and the noncollinear phasematching geometry in QPCPA,model and develop a novel noncollinear geometry in QPCPA,namely triple-wavelength phase-matching geometry,which provides two additional phase-matching points around the phase-matching point at the central wavelength.Our analysis demonstrates that the triple-wavelength phase-matching geometry can support stable,ultra-broadband amplification in QPCPA.The numerical simulation results show that ultrashort pulse with a pulse duration of 7.92 fs can be achieved in QPCPA when the pump intensity is limited to 5 GW/cm^(2),calculated using the nonlinear coefficient of YCa;O(BO;);.
基金This work was supported by the Natural Science Foundation of Shanghai(No.19YF1453600)the Key Task Project in Scientific and Technological Research on Social Development of Shanghai(No.20dz1206502)+2 种基金the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0102)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22000000)the Major Program of the National Natural Science Foundation of China(No.61991453)。
文摘A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching method,low-threshold OPO operation could be obtained compared with the configuration of collinear phase matching,and the maximum optical–optical conversion efficiency of 11.8%was achieved at 500 nm wavelength when 0.4 m J pump pulse energy was applied.When the noncollinearity angle was preset at 1.6°,4.8°,and 6.3°,a continuously tuning output with a total spectral range of 220 nm was successfully obtained by adjusting the phase matching angle of the BBO crystal.
