Bloch Wavefunction Interferometry of Driven Electron-Hole States

High Order Sideband Generation (HSG) occurs when a semiconductor is driven by a strong sub-THz field while probed with a weak near-infrared laser. We show the spectrum of sideband polarizations emitted from bulk GaAs can be viewed as the interferogram from a Michelson-like interferometer between the Bloch waves associated with two species of electron-hole pairs. A simple analytical model is used to calculate the dynamical phase accumulated by Bloch waves associated with E-HH and E-LH pairs. The measured and calculated interferograms are in good quantitative agreement, including scaling with THz field strength. The success of the analytical model makes it possible to probe the interferogram's dependence on other material parameters.