High Power Mid-infrared Quantum Cascade Lasers for BMDS and other applications

In Phase I we propose to demonstrate a room temperature continuous wave QC laser at 4.5µm with high power (P>0.5W) and wall plug efficiency (η>5%). The data will be used to design a high performance QC laser with projected wall plug efficiency exceeding 15% in continuous mode operation at room temperature. Our goal is to fabricate, characterize and package the high efficiency lasers in Phase II of the proposed project, and use beam combining methods to increase powers to above 3.5 W by combining six 1W single emitters with an estimated coupling efficiency of 65%. Preliminary sensing experiments, laser frequency modulation studies, and modeling of beam combining will also be carried out in Phase I with currently available lower efficiency lasers. The high efficiency devices will be designed at various possible emission wavelengths, ranging from the MWIR (3-5µm) to the LWIR (8-12µm). Modeling will take care of the three main aspects of efficiency improvement: heat management optimization, optical loss minimization, and electrical power reduction. The final phase I results will lead to a feasibility evaluation for a high power packaged laser with multiple high efficiency emitters combined in one rugged and portable package with estimates of its remote sensing and modulation capabilities.