Four-wave mixing and direct terahertz emission with two-color semiconductor lasers

Abstract

We have observed four-wave mixing in a semiconductor laser configured to emit on two wavelengths simultaneously. The four-wave mixing sidebands exist up to 4 THz stemming from a modulation of the carrier plasma at the difference frequency of the two laser modes. In addition, we were able to generate and detect tunable THz radiation at this difference frequency from the laser device itself suggesting a scheme for a tunable THz source.

Generation of Terahertz radiation with two color semiconductor lasers

“…The data indeed follow the transmission characteristics of the bandpass filter and thus unambiguously verify the direct emission of THz radiation at the THz difference frequency of the two color laser. Further evidence is given by microscopic calculations on the direct THz emission which are in good qualitative agreement with our experiments [60].…”

“…6 the nonlinearities in the carrier dynamics are not only responsible for the direct THz emission but also for the appearance of fourwave mixing sidebands. These might therefore be used to study the frequency response of the nonlinearities since they are clearly visible in the near infrared spectra [60]. Accordingly, we now discuss the frequency limitations of the nonlinearities by analyzing the FWM sidebands in two color operation.…”

Terahertz photomixer

“…a Fabry-Perot filter) are used [24]. Figure 7 presents another example where a sophisticated optical selector is used [25]. It is so called a V-shape mirror VSM and diffraction grating DG, as a specific optical selector OS -see Fig.…”

Terahertz Generation and Detection by Plasma Waves in Nanometer Gate High Electron Mobility Transistors

“…At present, there exist a few methods of generating THz radiation from solids: some of them are based on plasma excitations by femtosecond laser pulses in low dimensional [3] and bulk [4] semiconductors or superconductors [5] while other ones rely on mixing of laser beams with close frequencies [6]. These methods require advanced experimental equipments and their performance depends on a strong optical excitation of an appropriate semiconductor structure.…”