We conduct a frequency spectrum experiment to investigate terahertz（THz） emissions from laser-induced air plasma under different laser incident powers. The frequency spectra are measured using both air-biased-cohere...We conduct a frequency spectrum experiment to investigate terahertz（THz） emissions from laser-induced air plasma under different laser incident powers. The frequency spectra are measured using both air-biased-coherent detection and a Michelson interferometer. The red-shift of the THz pulse carrier frequency is observed as a response to increased pump power. These phenomena are related to plasma collisions and can be explained by the plasma collision model. Based on these findings, it is apparent that the tuning of the THz carrier frequency can be achieved through regulation of the pump beam.展开更多
Terahertz （THz） emission from laser-induced air-plasma is presented. The frequency spectra of THz wave are investigated using an air-biased-coherent-detection method. The frequency spectra are measured under differe...Terahertz （THz） emission from laser-induced air-plasma is presented. The frequency spectra of THz wave are investigated using an air-biased-coherent-detection method. The frequency spectra are measured under different pump-pulse and probe-pulse energies. The frequency pump power and we speculate it caused by collision behavior spectra become narrow with the increasing Meanwhile, the bandwidth of the frequency spectra is broadened by the increasing probe power, which can be explained by pulse compression. Based on this finding, the optimal frequency spectrum of THz can be achieved by regulating the probe and pump beam.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61377109 and 11374007)the Support Program for Outstanding Ph.D. Advisors,China(Grant No.YB20101000701)
文摘We conduct a frequency spectrum experiment to investigate terahertz（THz） emissions from laser-induced air plasma under different laser incident powers. The frequency spectra are measured using both air-biased-coherent detection and a Michelson interferometer. The red-shift of the THz pulse carrier frequency is observed as a response to increased pump power. These phenomena are related to plasma collisions and can be explained by the plasma collision model. Based on these findings, it is apparent that the tuning of the THz carrier frequency can be achieved through regulation of the pump beam.
基金the National Natural Science Foundation of China(Nos.11374007 and 61377109)the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(No.201237)the Support Program for Outstanding Ph.D.Advisors(No.YB20101000701)
文摘Terahertz （THz） emission from laser-induced air-plasma is presented. The frequency spectra of THz wave are investigated using an air-biased-coherent-detection method. The frequency spectra are measured under different pump-pulse and probe-pulse energies. The frequency pump power and we speculate it caused by collision behavior spectra become narrow with the increasing Meanwhile, the bandwidth of the frequency spectra is broadened by the increasing probe power, which can be explained by pulse compression. Based on this finding, the optimal frequency spectrum of THz can be achieved by regulating the probe and pump beam.
