Ring-Cavity Surface-Emitting Quantum Cascade Laser Array

Surface emitting semiconductor lasers eliminate the necessity for facet cleaving and allow for wafer scale testing, which increase the manufacturing yield and reduces the cost. However, in the mid-infrared, surface emitting semiconductor lasers are significantly underdeveloped compared to edge emitting devices. The proposed STTR Phase II research is to demonstrate a prototype using ring-cavity surface-emitting quantum cascade laser (QCL) array for power scaling at a wavelength of 4.5 microns. This approach allows for two-dimensional integration of multiple emitters on a single chip. A single mode emitting spectrum, excellent beam quality, and high power can be simultaneously achieved with this technology. The proposed high power mid-infrared laser sources are highly attractive for standoff spectroscopy, free-space communication and infrared countermeasure systems, in which cost, size, and weight are prime factors. Upon completion of the project, an inexpensive, compact, and lightweight mid-infrared laser source will be available for a much broader range of applications.