Generation of Low-frequency Components Due to Phase-amplitude Modulation of Subcycle Far-infrared Pulses in Near-field Diffraction
26 August 2002
We observe carrier phase dependent generation of low-frequency spectral components in the near-field zone of a subwavelength aperture illuminated by subcycle far-infrared (terahertz) pulses.
Diffraction induced II/2-phase shift of the pulse carrier results in the spectral intensity variation of the low-frequency components. The effect demonstrates that spectral content of subcycle pulses is not conserved under phase-shift transformations.