Generation of Ultrashort Electrical Pulses by Virtual Screening in Biased Quantum Wells.

We consider theoretically a semiconductor quantum well subject to an electrostatic field normal to the layer and a strong monochromatic laser field in the transparency region below the absorption edge. We show that ultrashort optical pulses will generate ultrashort voltage pulses because the virtual electron-hole population induced by the laser field will partially screen the applied static field. This will also transiently suppress the quantum-confined Stark effect. We predict voltages > 1 V could be generated in micron- thick multiple quantum well structures using low-power short-pulse lasers.