Chapter 8 - Harmonic generation using metal and semiconductor nanoparticles

Abstract

Inorganic nanoparticle-containing media can be used for the efficient high-order harmonic generation of laser radiation in the extreme ultraviolet range. We analyze the results of studies of the HHG in laser-produced plasmas-containing Ag, Au, Pd, Pt, Ru, GaN, BaTiO3, and SrTiO3 nanoparticles. The harmonics of femtosecond radiation up to the 55th order were achieved using the nanoparticle-containing plumes, when the femtosecond radiation propagated through the preformed plasma. We discuss a six-fold enhancement of the HHG yield, which was achieved in the case of nanoparticle-containing plumes with regard to the monoparticle-containing plasmas. Broadband harmonic generation was observed through the optimization of femtosecond laser intensity and through the use of spectrally broadened laser pulses. Efficient generation of even- and odd-order harmonics was observed through the use of two-color pulses. The results of the experimental study of HHG from the interaction of 45-fs Ti:sapphire laser pulses with plasma plumes of Ag nanoparticles produced in situ are discussed.