A Monte Carlo simulation of mode-locked hot-hole laser operation

We propose a method to achieve mode-locking in a p-germanium inter-valence-band laser by modulating its gain. This is done by applying an additional radiofrequency (RF) electric field parallel to the applied magnetic field. Due to the acceleration by this RF field, the light holes are no longer accumulated in the so-called passive region below the optical phonon energy and the population inversion between the light and heavy hole band decreases strongly. A single-particle Monte Carlo simulation is used to study this effect more quantitatively. It is shown that an RF field of only a few per cent of the applied DC electric field already yields a peak-to-peak gain modulation of 30-50%. It is estimated that by using this method for actively mode-locking a p-Ge inter-valence-band laser, picosecond FIR pulses of considerable power can be obtained.