Compact Mid-Infrared Laser Source

The objectives of this Phase I program is to demonstrate the feasibility of a new class of monolithic solid state quantum well lasers for the mid-infrared. The concept is based on the use of a novel electron Fabry-Perot interference effect which achieves population inversion by free electron injection at a convenient voltage level for highpower applications. The laser consists of a single stack of III-V semiconductor layers produced by advanced MBE techniques. Preliminary experiments have shown that the energy states have approximately the expected energy levels and cross sections. In Phase I the current density will be increased to lasing threshold and a prototype laser with one watt output will be fabricated. Actual lasing action will provide a demonstration of feasibility. In the option task a Ge waveguide approach will be studied for suitability for high power lasers. The use of Ge removes the need for AlAs cladding layers with AlGaAs MBE growth reduced by a factor of 10. Furthermore, removal of the AlAs cladding improves stability, reduces electron conductivity problems in the AlAs, and provides greater thermal conductivity for high power lasing.