Isolated-attosecond-pulse generation by suppressing multiple rescatterings with plasmon-enhanced laser fields

ABSTRACT

An efficient scheme is proposed to generate broadband supercontinuum spectra and isolated attosecond laser pulses by suppressing multiple rescatterings with plasmon-enhanced laser fields. High-order harmonic generation from helium atoms in long wavelength is theoretically investigated. It is found that a quantum path interference and a multiple rescatterings interference are two fundamental limitations against the smooth degree of harmonic spectra. Numerical results show that the coherent superposition state in combination with plasmon-enhanced laser fields is robust for broadband supercontinuum generation. Then an isolated 78-as pulse can be directly generated.

KEYWORDS:

• Isolated attosecond pulse
• multiple rescatterings
• plasmon-enhanced laser field
• superposition state

PACS NUMBERS:

• 42.65.ky
• 32.80.Qk
• 42.65.Re

Acknowledgments

The authors sincerely thank Prof. Keli Han and Dr. Ruifeng Lu for providing us the LZH-DICP code.