Difference Frequency Sideband Generation In Semiconductors

In this paper, a near-infrared (NIR) laser (with frequency omega(NIR)) exciting and an intense mid-infrared (MIR) bichromatic laser (with frequencies omega(1) and omega(2)) driving scheme is proposed in semiconductors. It is predicted that if the frequency difference between the two components of the MIR laser, i. e. Omega =omega(1)-omega(2), is in dozens of GHz frequency range, the emitting light contains spectra with frequencies omega =omega(NIR) + N Omega, where N is integer. In analogy with high-order THz sideband generation (HSG) in semiconductors, this phenomenon is named difference frequency sideband generation (DSG). Similar to the HSG case, the emitted sideband spectrum in DSG exhibits a nonperturbative plateau, where the intensity of the sideband remains approximately constant up to a cutoff frequency. The location of the cutoff frequency and its relationship with the frequency detuning of the NIR laser are discussed via the semi-classical saddle-point method. (c) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement