Fast recovery of excitonic absorption bleaching in tunneling biquantum well structures

This letter demonstrates the fast recovery from excitonic absorption bleaching in tunneling biquantum well structures. A tunneling biquantum well consists of a series of narrow and wide wells. Recovery time was reduced to 1 ps using 1.7-nm-thick tunneling barriers, three orders of magnitude shorter than the few nanoseconds recovery due to radiative recombination. This is the fastest tunneling process observed to date.