Aa. Belyanin et al., Infrared generation in low-dimensional semiconductor heterostructures via quantum coherence - art. no. 053803, PHYS REV A, 6305(5), 2001, pp. 3803
A scheme for infrared generation without population inversion between subba
nds in quantum-well and quantum-dot lasers is presented. The scheme is base
d on the resonant nonlinear mixing of the optical laser fields on the two i
nterband transitions that are generated in the same active region and that
serve as the coherent drive for the infrared field. This mechanism for freq
uency down-conversion does not rely upon any ad hoc assumptions of long-liv
ed coherences in the semiconductor active medium, and it should work effici
ently at room temperature with injection current pumping. For optimized wav
eguide and cavity parameters, the intrinsic efficiency of the down-conversi
on process can reach the limiting quantum value corresponding to one infrar
ed photon per one optical photon. Due to the parametric nature of infrared
generation, the proposed inversionless scheme is especially promising for l
ong-wavelength (far-infrared) operation.