Description: This proposal describes development of a new type of quantum-cascade laser for use as a local oscillator at frequencies above 2 THz. The THz source described is a single chip solution that operates at room temperature. In addition, a mechanism for wide tuning (2-4.7 THz) is described that requires no moving parts.

Benefits: Compact and reliable local oscillators at frequencies above 2 THz are highly sought after for environmental monitoring of planetary bodies. This is one of the primary components in the microwave limb sounder on the Aura satellite. There a multitude of environmentally relevant chemicals (e.g. OH H2S, HF, HBr) that can be monitored at frequencies >2 THz. This capability would be extremely useful to study the atmospheres of neighboring planets in our solar system. These frequencies are also sought after for monitoring molecular and atomic emission lines in the interstellar medium. In both cases, our compact THz source would provide a significant size, weight, and power (SWaP) savings over current gas laser-based solutions.

There are many other target applications for this technology, including: drug detection/ pharmaceutical use, security screening, and medical imaging. The narrow linewidth characteristic can provide a higher resolution alternative to time-domain spectroscopy (TDS) techniques currently in use. The potential also exists for targeting specific resonances within target molecules or conformations, in combination with infrared or fluorescence spectroscopy, to help isolate very small concentrations in complex mixtures.