High-order harmonic generation during propagation of femtosecond pulses through the laser-produced plasmas of semiconductors

The generation of high-order harmonics of the ultrashort pulses of Ti:sapphire laser in the plasma plumes produced during laser ablation of various semiconductors (Te, Se, Si, As, Sb, and Ge) is reported. Application of two-color pump allowed the generation of enhanced odd and even harmonics. The resonance-induced enhancement of single harmonics was observed in the Ge, Se, Sb, As, and Te plasmas. The enhanced 35th harmonic obtained from selenium plasma was twelve times stronger than the neighboring harmonics. We also demonstrate the quasi-phase-matching of the harmonics generated in the As plasma. (C) 2015 AIP Publishing LLC.