Infrared generation in low-dimensional semiconductor heterostructures via quantum coherence - art. no. 053803

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.