Amplification of mid- and far-IR pulses in synchronously pumped low-dimensional heterostructures

The synchronous propagation of optical pulses and mid- and far-IR pulses in waveguide low-dimensional quantum-well semiconductor heterostructures is considered. It is shown that low-frequency radiation can be considerably amplified in these systems even at room temperature because a high-power high-frequency pulse produces transient population inversion at the corresponding low-frequency transition formed by the dimensional quantisation levels of the semiconductor. The optimal parameters of the pump optical pulse and heterostructure are determined at which mid- or far-IR picosecond pulses of power ~100 mW or 0.1 mW, respectively, can be amplified by more than two orders of magnitude without considerable changes in their duration and shape.