Over the past three decades a new spectroscopic technique with unique possibilities has
emerged. Based on coherent and time‐resolved detection of the electric field of ultrashort …

Chemical and physical systems undergoing change display spectral signatures from the
radio frequency to the X-ray region of the electromagnetic spectrum. This has led to the …

Weyl semimetals are crystals in which electron bands cross at isolated points in momentum
space. Associated with each crossing point (or Weyl node) is a topological invariant known …

We describe a new four-wave rectification method for the generation of intense, ultrafast
terahertz (THz) pulses from gases. The fundamental and second-harmonic output of an …

We propose a generally applicable velocity matching method for THz-pulse generation by
optical rectification in the range below the phonon frequency of the nonlinear material …

A detailed calculation of the amplitude and phase response of ultrathin ZnTe and GaP
electro-optic sensors is presented. We demonstrate that the inclusion of the dispersion of the …

We review the generation of broadband THz radiation from femtosecond photo‐induced gas
plasmas, with an emphasis on the highly efficient “AC‐bias” case where the plasma is …

We present a complete frequency-domain description of electro-optic (EO) detection of
terahertz (THz) electromagnetic radiation, including a description of the ellipsometry …

Bandwidth-limited infrared pulses as short as 50 fs are generated in thin GaSe crystals by
phase-matched optical rectification of 10 fs laser pulses. The central frequency of the …

We present a combined theoretical and experimental investigation of the generation of few-
cycle terahertz (THz) pulses via the nonlinear effect of optical rectification and of their …