Detecting the propagation effect of terahertz wave inside the two-color femtosecond laser filament in the air
In this work, to decide the existence of terahertz (THz) wave propagation effect, THz pulses emitted from a blocked two-color femtosecond laser filament with variable length were recorded by a standard electric–optic sampling setup. The phenomenon of temporal advance of the THz waveform’s peak with the increasing filament length has been observed. Together with another method of knife-edge measurement which aims at directly retrieving the THz beam diameter, both the experimental approaches have efficiently indicated the same filament range within which THz wave propagated inside the plasma column. At last, a preliminary two-dimensional near-field scanning imaging of the THz spot inside the cross section of the filament has been suggested as the third way to determine the issue of THz wave propagation effect.
National Key R&D Program of China (2017YFC0821300), National Natural Science Foundation of China (11704252, 11574160, 61722111), National Program on Key Basic Research Project of China (973 Program) (2014CB339802, 2014CB339806), the Major National Development Project of Scientific Instrument and Equipment (2017YFF0106300, 2016YFF0100503), the Key Scientific and Technological Project of Science and Technology Commission of Shanghai Municipality (15DZ0500102), Shanghai leading talent (2016-019), and Young Yangtse Rive Scholar (Q2016212).
- 29.J. Zhao, W. Liu, S. Li, D. Lu, Y. Zhang, Y. Peng, Y. Zhu, S. Zhuang, New clue to thorough understanding terahertz pulse generation by femtosecond laser filamentation Photonics Res. Accepted manuscript (2018)Google Scholar