Resonator creates powerful single-mode laser sources

According to the university, infrared radiation in the range of 8–12 microns is of interest for military and industrial use equally, as almost all chemicals — including nerve gases and toxic industrial chemicals — can be identified by infrared absorption in this range. In addition, the atmosphere is relatively transparent in this wavelength range, which enables sensing from a distance.



Stand-off sensing applications, however, require that laser sources be high powered and single mode, and possess good beam quality. Incorporating all three qualities in a single device presents a significant challenge, and many sophisticated structures are said to have been proposed with little success.


Manijeh Razeghi, the Walter P Murphy professor of electrical engineering and computer science in the McCormick School of Engineering and Applied Science, and her group have created a new laser technology that controls both wavelength and beam quality.

The feat is achieved through the use of a new type of distributed feedback mechanism called Β-DFB, a simple diffractive feedback in an angled laser cavity.