Researchers demonstrate 100-watt-level mid-infrared lasers

Dec 01, 2009

Northwestern University researchers have achieved a breakthrough in quantum cascade laser output power, delivering 120 watts from a single device at room temperature.

The results are particularly attractive for infrared countermeasure, a way of misguiding incoming missiles to protect commercial and military aircrafts.

The research, led by Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science at the McCormick School of Engineering and Applied Science, was published in the journal on Dec. 1.

Unlike conventional interband semiconductor lasers, such as those used in DVD players, the quantum cascade (QCL) is an intersubband device that requires only electrons to operate. Because of this fundamental difference, a QCL shows unique properties that a conventional laser lacks. One of these properties is that the linewidth enhancement factor of a QCL is close to zero, compared to two to five for a conventional laser. This difference has serious implications in terms of power scaling with broad-area devices.

Researchers at the Center for Quantum Devices at Northwestern, led by Razeghi, found that the QCL is exceptionally resistant to filiamentation, a phenomenon that limits the ridge width of conventional broad-area semiconductor lasers. In this work, Razeghi's team demonstrated that the ridge width of a broad-area QCL can be increased up to 400 microns, without suffering from filiamentation. As a result, room temperature peak output power as high as 120 watts was obtained from a single device, which is up from 34 watts only a year ago.

Source: Northwestern University (news : web)

Explore further: Physicists provide new insights into the world of quantum materials

add to favorites email to friend print save as pdf

Related Stories

Tiny infrared laser holds promise as weapon against terror

Aug 05, 2005

The difficulty of detecting the presence of explosives and chemical warfare agents (CWAs) is once again all too apparent in the news about the London bombings. In a significant breakthrough, researchers at Northwestern Uni ...

New mid-infrared lasers show doubled efficiency

May 19, 2008

Researchers at the Center for Quantum Devices at the McCormick School of Engineering at Northwestern University have recently doubled the efficiency of infrared lasers under the U.S. Defense Advanced Research Projects Agency’s ...

Controlling light with light

Jun 12, 2004

''Interband transitions controlling intersubband transitions'' is the technical description for what has been achieved in an optics lab in Stevens Institute of Technology’s Physics Department. Robert K. Murawski, a post-doctoral ...

Recommended for you

Quantum mechanics to charge your laptop?

Sep 18, 2014

Top scientists from UC Berkeley and MIT found the expertise they lacked at FIU. They invited Sakhrat Khizroev, a professor with appointments in both medicine and engineering, to help them conduct research ...

Physicists design zero-friction quantum engine

Sep 16, 2014

(Phys.org) —In real physical processes, some energy is always lost any time work is produced. The lost energy almost always occurs due to friction, especially in processes that involve mechanical motion. ...

Fluid mechanics suggests alternative to quantum orthodoxy

Sep 12, 2014

The central mystery of quantum mechanics is that small chunks of matter sometimes seem to behave like particles, sometimes like waves. For most of the past century, the prevailing explanation of this conundrum ...

User comments : 0