Anti-Correlated Plasma and THz Pulse Generation during Two-Color Laser Filamentation in Air

Autor: Zhiqiang Yu, Lu Sun, Nan Zhang, Jianxin Wang, Pengfei Qi, Lanjun Guo, Quan Sun, Weiwei Liu, Hiroaki Misawa
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Ultrafast Science, Vol 2022 (2022)
Druh dokumentu: article
ISSN: 2765-8791
DOI: 10.34133/2022/9853053
Popis: The THz generation efficiency and the plasma density generated by a filament in air have been found anti-correlated when pumped by 800 nm+1600 nm two-color laser field. The plasma density near zero delay of two laser pulses has a minimum value, which is opposite to the trend of THz generation efficiency and contradicts common sense. The lower plasma density cannot be explained by the static tunneling model according to the conventional photocurrent model, but it might be attributed to the electron trapping by the excited states of nitrogen molecule. The present work also clarifies the dominant role of the drifting velocity accelerated by the two-color laser field during the THz pulse generation process. The results promote our understanding on the optimization of the THz generation efficiency by the two-color laser filamentation.
Databáze: Directory of Open Access Journals