New laser hits mark on cancer imaging to airport security
The terahertz frequency range — which sits in the middle of the electromagnetic spectrum between microwaves and infrared light — offers the potential for high-bandwidth communications, ultrahigh-resolution imaging, precise long-range sensing for radio astronomy, and much more. But this section of the electromagnetic spectrum has remained out of reach for most applications. That is because current sources of terahertz frequencies are bulky, inefficient, have limited tuning, or must operate at low temperature. Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with the Massachusetts Institute of Technology and the U.S. Army, have developed a compact, room-temperature, widely tunable terahertz laser. The research is published in Science. “This laser outperforms any existing laser source in this spectral region and opens it up, for the first time, to a broad range of applications in science and technology,” said Federico Capasso, the Robert L. Wallace Professor of Applied Physics...