Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ...Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ← X^(1) Σ_(g)^(+) ( v = 0 ) transitions. Highly resolved third harmonic spectrum exhibits some distinct characteristics. Phase-matching effect of the nonlinear optical process is also discussed.展开更多
Tunalbe coherent extreme ultraviolet radiation has been produced in nitrogen by third harmonic generation(THG)processes enhanced by two-photon resonance with the a^(1)II_(g)(v'=1)state and three-photon resonance w...Tunalbe coherent extreme ultraviolet radiation has been produced in nitrogen by third harmonic generation(THG)processes enhanced by two-photon resonance with the a^(1)II_(g)(v'=1)state and three-photon resonance with the c'_(4)^(1)Σ_(u)^(+)(v'=1)state,respectively.The highly resolved THG spectra imply that THG can be used to probe the higher excited states and to detect the rotational population of a molecular gas.展开更多
Tunable coherent extreme ultraviolet radiation has been generated in CO by two-photon resonant third harmonic generation via the A^(1) II(v'=4)←X^(1)Σ+(v"=0)transition.The third nharmonic spectrum exhibits ...Tunable coherent extreme ultraviolet radiation has been generated in CO by two-photon resonant third harmonic generation via the A^(1) II(v'=4)←X^(1)Σ+(v"=0)transition.The third nharmonic spectrum exhibits resolved and improved rotational lines due to the expansion cooling of the molecular beam.The saturation and the phase-matching of the nonlinear process are also discussed.展开更多
Tunable coherent radiation of wavelength between 92 nm and 122 nm has been produced in molecular gases of N2, CO, H2 and CH4 by resonant and nonresonant third harmonic generation. Factors with respect to the frequency...Tunable coherent radiation of wavelength between 92 nm and 122 nm has been produced in molecular gases of N2, CO, H2 and CH4 by resonant and nonresonant third harmonic generation. Factors with respect to the frequency conversion efficiency, including the line strength of the nonlinear susceptibility, the density of the media and the phase-matching, are discussed. By analyzing the characteristics of the four-wave mixing spectra in molecular gases, some physical parameters and the population of the energy levels are obtained. This indicates that nonlinear optical frequency conversion process provides a useful method to study the structure and spectra of molecules.展开更多
Laser tweezers can manipulate small particles, such as cells and organdies. When coupling them with laser microbeam selective fusion of two tobacco protoplasts containing some chloroplast was achieved. Physical and bi...Laser tweezers can manipulate small particles, such as cells and organdies. When coupling them with laser microbeam selective fusion of two tobacco protoplasts containing some chloroplast was achieved. Physical and biological variables that affect laser trapping and laser-induced fusion were also discussed. The results show that the effect of chloroplast content and distribution on the yield of cell fusion is remarkable.展开更多
基金the National High Technology Program of Lasers(863-410).
文摘Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ← X^(1) Σ_(g)^(+) ( v = 0 ) transitions. Highly resolved third harmonic spectrum exhibits some distinct characteristics. Phase-matching effect of the nonlinear optical process is also discussed.
基金Supported by the High Technology Program of Lasers(863-410)the National Natural Science Foundation of China under Grant No.19584001.
文摘Tunalbe coherent extreme ultraviolet radiation has been produced in nitrogen by third harmonic generation(THG)processes enhanced by two-photon resonance with the a^(1)II_(g)(v'=1)state and three-photon resonance with the c'_(4)^(1)Σ_(u)^(+)(v'=1)state,respectively.The highly resolved THG spectra imply that THG can be used to probe the higher excited states and to detect the rotational population of a molecular gas.
基金Supported by the High Technology Program of Lasers(863-410)the National Natural Science Foundation of China under Grant No.19584001.
文摘Tunable coherent extreme ultraviolet radiation has been generated in CO by two-photon resonant third harmonic generation via the A^(1) II(v'=4)←X^(1)Σ+(v"=0)transition.The third nharmonic spectrum exhibits resolved and improved rotational lines due to the expansion cooling of the molecular beam.The saturation and the phase-matching of the nonlinear process are also discussed.
文摘Tunable coherent radiation of wavelength between 92 nm and 122 nm has been produced in molecular gases of N2, CO, H2 and CH4 by resonant and nonresonant third harmonic generation. Factors with respect to the frequency conversion efficiency, including the line strength of the nonlinear susceptibility, the density of the media and the phase-matching, are discussed. By analyzing the characteristics of the four-wave mixing spectra in molecular gases, some physical parameters and the population of the energy levels are obtained. This indicates that nonlinear optical frequency conversion process provides a useful method to study the structure and spectra of molecules.
基金Project supported by the National Natural Science Foundation of China (Grant No. 39470205)State Science and Technology Commision, and Science and Technolgy Commision of Anhui Province
文摘Laser tweezers can manipulate small particles, such as cells and organdies. When coupling them with laser microbeam selective fusion of two tobacco protoplasts containing some chloroplast was achieved. Physical and biological variables that affect laser trapping and laser-induced fusion were also discussed. The results show that the effect of chloroplast content and distribution on the yield of cell fusion is remarkable.
