First experiments and prospects of intracavity difference -frequency generation of mid/far-infrared and terahertz radiation in diode lasers

Our experimental and theoretical investigations in the field of new semiconductor sources of coherent mid/far-IR radiation based on the intracavity nonlinear mixing of close-in-frequency optical fields in dual-wavelength diode lasers are reviewed. Perspective schemes of quantum-well heterolasers of this kind are considered, and the ways of increasing the power of difference-frequency radiation are suggested, including the use of mode-locked lasers and hybrid surface-emitting grating-outcoupled lasers.