High Harmonic Generation by Plasmonic Enhancement of Femtosecond Pulse Laser.

Coherent EUV light is generated directly from a modest femtosecond laser whose pulse intensity reaches only 10¹¹ W cm^{− 2}. This value is in fact two orders of magnitude lower than the threshold pulse intensity required for high harmonic generation using noble gases. The key to this achievement is the plasmonic field enhancement by means of metallic nanostructures fabricated in bow-tie shape. This method requires no extra cavities for amplification of pulse intensity and thereby could form the basis to construct laptop-sized coherent EUV sources for many advanced applications lithographic and high-resolution imaging. [ABSTRACT FROM AUTHOR]