We investigate macroscopic interference effects in high-order harmonic generation using a Ti:sapphire laser operating at a 100 kHz repetition rate. The structure and behavior of spectral and spatial interference fringes are explained and analytically described by transient phase matching of the long electron trajectory contribution. Time-frequency mapping due to the temporal chirp of the harmon...

We investigate high-order harmonic generation in a sequence of icosahedral fullerenes using the extension of the so-called three-step or Lewenstein model to the molecular case. The high harmonic spectra obtained at midinfrared wavelengths show modulations in the plateau region. These modulations are due to the coherent superposition of the contributions from the atomic centers in the molecule t...

This paper presents practical experiments on a harmonic rejection down-mixer, which offers up to 75 dB of harmonic rejection, without an RF filter. The down-mixer uses a two-stage approach; the first stage is an analog multi-path/multiphase harmonic rejection mixer followed by a second stage providing additional harmonic rejection based on blind adaptive interference canceling in the discrete-t...