Temperature and Pump Pulse Dependence of Superfluoresence from InGaAs/GaAs Multiple Quantum Well in High Magnetic Fields

Using intense near-IR ultrashort pulse laser excitation, we investigate the characteristics of cooperative emission (superfluoresence) from dense electron hole magneto-plasmas in InGaAs/GaAs MQW in high magnetic fields as a function of temperature and excitation pulsewidth. We find strong narrow line emissions from 0-0 and 1-1 Landau levels (LLs), with thresholds depending on magnetic field and temperature. Varying the excitation pulsewidth (180 fs -- 60 ps) and fluence (0.1 -- 1 mJ/cm$^{2})$, we observe qualitative changes in the emission strengths from different LLs. The strong emissions from 0-0 and 1-1 LL excited with short and long pulses are obviously different. Mechanisms of the temperature and excitation pulse width effect on the strong emission are presented.