Optical switch of electron-hole and electron-electron collisions in semiconductors

Optoelectronic information devices are being developed to achieve an ultrafast speed, an ultrasmall size, and an ultralow power consumption. Here, the authors demonstrate the precise switch of two light wave driven carrier dynamic processes in semiconductors by using a weak control laser. One is the electron-hole collision recombination leading to high-order harmonic generation. The other is the electron-electron impact excitation leading to stimulated simulation. This all-optical switch has an ultrafast speed, a low threshold, and a broad spectral responsiveness.