Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using optical fiber to generate a two-micron laser

09.10.2015

Lasers with a wavelength of two microns could move the boundaries of surgery and molecule detection. Researchers at EPFL have managed to generate such lasers using a simple and inexpensive method

In recent years, two-micron lasers (0.002 millimetre) have been of growing interest among researchers. In the areas of surgery and molecule detection, for example, they offer significant advantages compared to traditional, shorter-wavelength lasers.


Camille Bres and Svyatoslav Kharitonov describe a cost-effective way to generate two-micron lasers, using only thulium-doped optical fibers instead of amplifiers and isolators.

Credit: Alban Kakulya / EPFL

However, two-micron lasers are still in their infancy and not yet as mature as their telecom counterparts (1.55-micron). Moreover sources currently used in labs are typically bulky and expensive. Optical fibre-based 2 micron lasers are an elegant solution to these issues. This is where researchers at Photonics Systems Laboratory (PHOSL) come in.

In an article published in Light: Science & Applications, the team of Camille Brès at EPFL described a way to design these lasers at a lower cost, by changing the way optical fibres are connected to each other.

Thanks to the new configuration, they were able not only to produce very good 2 micron lasers, but also to do without an expensive and complex component that is normally required.

Bloodless surgery and long-range molecule détection

Two-micron spectral domain has potential applications in medicine, environmental sciences and industry. At these wavelengths, the laser light is easily absorbed by water molecules, which are the main constituents of human tissue.

In the realm of high precision surgery, they can be used to target water molecules during an operation and make incisions in very small areas of tissue without penetrating deeply. What is more, the energy from the laser causes the blood to coagulate on the wound, which prevents bleeding.

Two-micron lasers are also very useful for detecting key meteorological data over long distances through the air. Not to mention that they are highly effective in the processing of various industrial materials.

Replacing a cop with a detour

To create a 2 micron fibre-laser, light is usually injected into an optical-fibre ring containing a gain region which amplifies 2 micron light. The light circulates in the ring, passing through the gain region many times thus gaining more and more power, until becoming a laser. For optimal operation, these systems include a costly component called isolator, which forces the light to circulate in a single direction.

At PHOSL, researchers built a thulium-doped fibre laser that works without an isolator. Their idea was to connect the fibres differently, to steer light instead of stopping it.

"We plug a kind of deviation that redirects the light heading in the wrong direction, putting it back on track", said Camille Brès. This means no more need for the isolator, whose job is to stop light moving in the wrong direction, sort of like a traffic cop. "We replaced the traffic cop with a detour," said Svyatoslav Kharitonov, the article's lead author.

Higher quality laser

The new system not only proved to be less expensive than more traditional ones, it also showed it could generate a higher quality laser light. The explanation is as follows: the laser output gets purified because light interacts with itself in a very special way, thanks to the amplifying fibre's composition and dimensions, and the high power circulating in this atypical laser architecture.

"While the association of amplifying fibres and high power usually weakens traditional lasers performance, it actually improves the quality of this laser, thanks to our specific architecture", said Svyatoslav Kharitonov.

###

Publication: Light: Science & Applications, Isolator-free unidirectional thulium doped fibre laser

Media Contact

Camille Bres
camille.bres@epfl.ch
41-216-937-866

 @EPFL_en

http://www.epfl.ch/index.en.html 

Camille Bres | EurekAlert!

More articles from Process Engineering:

nachricht Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>