Researchers build world's most powerful terahertz laser chip

Feb 17, 2014 by Chris Bunting

(Phys.org) —University of Leeds researchers have taken the lead in the race to build the world's most powerful terahertz laser chip.

A paper in the Institution of Engineering and Technology's (IET) journal Electronics Letters reports that the Leeds team has 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.

Widely publicised 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.

Professor Edmund Linfield, Professor of Terahertz Electronics in the University's School of Electronic and Electrical Engineering, said: "Although it is possible to build large instruments that generate powerful beams of , these instruments are only useful for a limited set of applications. We need terahertz lasers that not only offer high power but are also portable and low cost."

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

Professor Linfield said: "The process of making these lasers is extraordinarily delicate. Layers of different semiconductors such as gallium arsenide are built up one atomic monolayer at a time. We control the thickness and composition of each individual layer very accurately and build up a semiconductor material of between typically 1,000 and 2,000 layers. The record power of our new laser is due to the expertise that we have developed at Leeds in fabricating these layered semiconductors, together with our ability to engineer these materials subsequently into suitable and powerful devices."

Professor Giles Davies, Professor of Electronic and Photonic Engineering in the School of Electronic and Electrical Engineering, said: "The University of Leeds has been an international leader in terahertz engineering for many years. This work is a key step toward increasing the power of these lasers while keeping them compact and affordable enough to deliver the range of applications promised by ."

Explore further: The world's most powerful terahertz quantum cascade laser

More information: Lianhe Li, Li Chen, Jingxuan Zhu, J. Freeman, P. Dean, A. Valavanis, A.G. Davies and E.H. Linfield, "Terahertz quantum cascade lasers with >1 W output powers," Electronics Letters (2014) The open-access article is available here: digital-library.theiet.org/content/journals/10.1049/el.2013.4035

add to favorites email to friend print save as pdf

Related Stories

New vacuum power amplifier demonstrated at 0.85 Terahertz

Nov 22, 2013

The submillimeter wave, or terahertz, part of the electromagnetic spectrum falls between the frequencies of 0.3 and 3 terahertz, between microwaves and infrared light. Historically, device physics has prevented ...

Recommended for you

Using antineutrinos to monitor nuclear reactors

3 hours ago

When monitoring nuclear reactors, the International Atomic Energy Agency has to rely on input given by the operators. In the future, antineutrino detectors may provide an additional option for monitoring. ...

Imaging turns a corner

7 hours ago

(Phys.org) —Scientists have developed a new microscope which enables a dramatically improved view of biological cells.

Mapping the road to quantum gravity

21 hours ago

The road uniting quantum field theory and general relativity – the two great theories of modern physics – has been impassable for 80 years. Could a tool from condensed matter physics finally help map ...

User comments : 0

More news stories

A 'quantum leap' in encryption technology

Toshiba Research Europe, BT, ADVA Optical Networking and the National Physical Laboratory (NPL), the UK's National Measurement Institute, today announced the first successful trial of Quantum Key Distribution ...

Phase transiting to a new quantum universe

(Phys.org) —Recent insight and discovery of a new class of quantum transition opens the way for a whole new subfield of materials physics and quantum technologies.

Bake your own droplet lens

A droplet of clear liquid can bend light, acting as a lens. Now, by exploiting this well-known phenomenon, researchers have developed a new process to create inexpensive high quality lenses that will cost ...

When things get glassy, molecules go fractal

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common—they all belong to a state of matter known as glasses. School children learn the difference between ...

Genetic code of the deadly tsetse fly unraveled

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Ocean microbes display remarkable genetic diversity

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...