Home » Harvard John A. Paulson School of Engineering and Applied Sciences » A leap-ahead technology for generating terahertz radiation
Progress

A leap-ahead technology for generating terahertz radiation

Harvard John A. Paulson School of Engineering and Applied Sciences

via Harvard John A. Paulson School of Engineering and Applied Sciences

New laser could be used for applications in imaging, security, or communications

Researchers have taken a major step towards bringing terahertz frequencies out of their hard-to-reach region of the electromagnetic spectrum and into everyday applications. In a new paper, the researchers demonstrate a first-of-its-kind terahertz laser that is compact, operates at room temperature and can produce 120 individual frequencies spanning the 0.25 – 1.3 THz, far more range than previous terahertz sources.

The laser could be used in a range of applications, such as skin and breast cancer imaging, drug detection, airport security and ultrahigh-capacity optical wireless links.

The research, conducted by a team from at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with the DEVCOM Army Research Lab and DRS Daylight Solutions, is published in APL Photonics.

“This is a leap-ahead technology for generating terahertz radiation,” said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS and senior author of the paper.  “Thanks to its compactness, efficiency, wide tuning range, and room temperature operation, this laser has the potential to become a key technology to bridge the terahertz gap for applications in imaging, security, or communications.”

The terahertz frequency range – which sits in the middle of the electromagnetic spectrum between microwaves and infrared light — has remained difficult to reach for applications because most terahertz sources are either very bulky, inefficient, or rely on low-temperature devices to produce these elusive frequencies with limited tuning.

In 2019, the Capasso Group, in collaboration with MIT and the U.S. Army, developed a prototype that proved terahertz frequency sources could be compact, room temperature and widely tunable by combing a quantum cascade laser pump with a nitrous oxide molecular laser.

The new research more than triples the tuning range of that prototype. Among other advances, the new laser replaces nitrous oxide with methyl fluoride, a molecule that reacts strongly with optical fields.

“This compound is really good at absorbing infrared and emitting terahertz,” said Arman Amirzhan, a graduate student at SEAS and first author of the paper. “By using methyl fluoride, which is non-toxic, we increased the efficiency and tuning range of laser.”

“Methyl fluoride has been used as a terahertz laser for almost 50 years, but it only generates a couple of laser frequencies when pumped by a bulky carbon dioxide laser,” said Henry Everitt, the U.S. Army’s senior technologist for optical sciences, and co-author of the paper. “The two innovations we report, a compact laser cavity pumped by a quantum cascade laser, combine to give methyl fluoride the ability to lase on hundreds of lines.”

This laser already has the potential to be one of the most compact terahertz lasers ever designed and the researchers aim to make it even more compact.

“A less than a cubic foot device will enable us to target this frequency range for even more applications in short-range communications, short-range radar, biomedicine and imaging,” said Paul Chevalier, a research associate at SEAS and lead researcher of the team.

“The combination of mature, compact, quantum cascade lasers with molecular laser gain media has resulted in a very robust THz laser platform with a wide range of applications from fundamental research, to THz molecular detection and imaging, THz communications and security and beyond,” said Timothy Day, Senior Vice President and General Manager of DRS Daylight Solutions and co-author of the paper.

 

Original Article: A leap forward for terahertz lasers

More from: Harvard John A. Paulson School of Engineering and Applied Sciences 

 

The Latest on: Terahertz lasers

  • Flexible method for shaping laser beams extends depth-of-focus for OCT imaging
    on July 28, 2022 at 7:30 am

    Researchers have developed a new method for flexibly creating various needle-shaped laser beams. These long, narrow beams can be used to improve optical coherence tomography (OCT), a ...

  • Advances in Laser Physics and Technology
    on July 27, 2022 at 10:42 pm

    Lasers are created to study the timescale of electron motion in atoms and molecules. They also have wide applications in areas like solid state, plasma physics, nanoscience and defence technology.

  • Shaping laser beams boosts OCT depth of focus
    on July 26, 2022 at 2:09 am

    Needle-shaped laser beams (NBs) featuring a long and narrow localization ... "Our model can also be applied to electromagnetic waves for terahertz imaging and even the mechanical waves used in ...

  • Terahertz Components and Systems Market 2022 | Guaranteed 30% OFF | Size, Share, Trend : What is the current value for Industry till 2030?
    on July 5, 2022 at 9:09 pm

    M Squared Lasers and other key market players. The Terahertz Components and Systems market revenue was $$ Million USD in 2016, grew to $$ Million USD in 2022, and will reach $$ Million USD in 2030 ...

  • Physical Foundations of IT Security Group
    on June 28, 2022 at 3:32 pm

    The Physical Foundations of IT Security Group in the Department of Terahertz and Laser Spectroscopy focus is on fundamental methods and technologies as well as on applications for optical quantum ...

  • Time-Domain Spectroscopy group
    on June 28, 2022 at 3:32 pm

    The Time-Domain Spectroscopy group in the Department of Terahertz and Laser Spectroscopy has a long track record in instrumentation development and has in recent years pioneered terahertz time-domain ...

  • Saser, The Sound Laser Developed
    on June 18, 2022 at 5:00 pm

    able to create highly focused beams of sound in the terahertz frequency range. Considering the impact that lasers had on optics and the world as a whole, the possibilities for an acoustic version ...

  • Topologically tuned terahertz on a nonlinear photonic chip
    on June 8, 2022 at 5:57 pm

    The team used femtosecond-laser writing technology to develop the construct with a topological defect at the central interface. They measured the terahertz field via pump-probe experiment to show ...

  • Kennedy College of Sciences
    on January 28, 2022 at 1:04 pm

    Under the direction of Giles is a 20-member research team, with several dozen graduate and undergraduate students, who build and maintain a variety of high-performance solid-state and laser-based ...

  • Terahertz quantum-cascade lasers
    on December 2, 2021 at 7:01 pm

    Six years after their birth, terahertz quantum-cascade lasers can now deliver milliwatts or more of continuous-wave coherent radiation throughout the terahertz range — the spectral regime ...

via Bing News

The Latest on: Terahertz lasers

via Google News

Add Comment

Click here to post a comment

Your thoughtful comments are most welcome!

This site uses Akismet to reduce spam. Learn how your comment data is processed.