World's most powerful terahertz laser chip developed

British researchers have built the world's most powerful terahertz laser chip, an advance that may enable improved security scanning and medical imaging.

Researchers from the University of Leeds claimed to have exceeded a 1 Watt output power from a quantum cascade terahertz laser. The new record more than doubles landmarks set by the Massachusetts Institute of Technology (MIT) and subsequently by a team from Vienna last year.

Terahertz waves, which lie in the part of the electromagnetic spectrum between infrared and microwaves, can penetrate materials that block visible light and have a wide range of possible uses including chemical analysis, security scanning, medical imaging, and telecommunications.

Potential applications include monitoring pharmaceutical products, the remote sensing of chemical signatures of explosives in unopened envelopes, and the non-invasive detection of cancers in the human body.

However, one of the main challenges for scientists and engineers is making the lasers powerful and compact enough to be useful.

"Although it is possible to build large instruments that generate powerful beams of terahertz radiation, these instruments are only useful for a limited set of applications," said Edmund Linfield, Professor of Terahertz Electronics in the University's School of Electronic and Electrical Engineering.

"We need terahertz lasers that not only offer high power but are also portable and low cost," Linfield said. The quantum cascade terahertz lasers being developed by Leeds are only a few square millimetres in size.

In October 2013, Vienna University of Technology announced that its researchers had smashed the world record output power for quantum cascade terahertz lasers previously held by Massachusetts Institute of Technology (MIT).

The Austrian team reported an output of 0.47 Watt from a single laser facet, nearly double the output power reported by the MIT team. The Leeds group has now achieved an output of more than 1 Watt from a single laser facet.

The research was published in the Institution of Engineering and Technology's (IET) journal Electronics Letters.