中国物理B ›› 2014, Vol. 23 ›› Issue (1): 14201-014201.doi: 10.1088/1674-1056/23/1/014201

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Low temperature enhancement of alignment-induced spectral broadening of femtosecond laser pulses

王翡, 蒋红兵, 龚旗煌   

  1. Department of Physics & State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871, China
  • 收稿日期:2013-08-21 修回日期:2013-10-10 出版日期:2013-11-12 发布日期:2013-11-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grants Nos. 11074014 and 11121091).

Low temperature enhancement of alignment-induced spectral broadening of femtosecond laser pulses

Wang Fei (王翡), Jiang Hong-Bing (蒋红兵), Gong Qi-Huang (龚旗煌)   

  1. Department of Physics & State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871, China
  • Received:2013-08-21 Revised:2013-10-10 Online:2013-11-12 Published:2013-11-12
  • Contact: Jiang Hong-Bing E-mail:hbjiang@pku.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grants Nos. 11074014 and 11121091).

摘要: The propagation of femtosecond laser pulses in N2-filled hollow fibers is studied both theoretically and experimentally. The laser pulse aligns the N2 molecules and changes the refractive index, which meanwhile modulates the spectrum of the pulse in turn. The dependence of the spectral modulation on the gas temperature is investigated. We find that both spectral broadening and frequency red-shift are enhanced at low temperature. The degree of enhancement is found to be dependent on the pulse duration. Based on our findings, we propose a method for femtosecond pulse spectral broadening and few-cycle pulse generation via the molecular alignment.

关键词: field-free molecular alignment, femtosecond phenomenon, ultrafast nonlinear optics

Abstract: The propagation of femtosecond laser pulses in N2-filled hollow fibers is studied both theoretically and experimentally. The laser pulse aligns the N2 molecules and changes the refractive index, which meanwhile modulates the spectrum of the pulse in turn. The dependence of the spectral modulation on the gas temperature is investigated. We find that both spectral broadening and frequency red-shift are enhanced at low temperature. The degree of enhancement is found to be dependent on the pulse duration. Based on our findings, we propose a method for femtosecond pulse spectral broadening and few-cycle pulse generation via the molecular alignment.

Key words: field-free molecular alignment, femtosecond phenomenon, ultrafast nonlinear optics

中图分类号:  (Nonlinear optics)

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