Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMD physicists discover 'smoke rings' made of laser light

09.09.2016

3-D ring structures made by high-intensity lasers could aid the design of powerful microscopes and more efficient telecommunication lines

Most basic physics textbooks describe laser light in fairly simple terms: a beam travels directly from one point to another and, unless it strikes a mirror or other reflective surface, will continue traveling along an arrow-straight path, gradually expanding in size due to the wave nature of light. But these basic rules go out the window with high-intensity laser light.


Orbital angular momentum (OAM) vortices (pink ringlike objects) are three-dimensional laser light structures that rotate around a central beam, much like water circles around a drain. Physicists and engineers have studied this type of laser vortex since the 1990s as a tool to help improve microscopy and telecommunications.

Credit: Howard Milchberg


Spatiotemporal optical vortices, or STOVs (thin, gray ringlike objects), are newly described three-dimensional light structures that strongly resemble smoke rings. Unlike other laser vortices, STOVs are time dynamic, which means that they travel along with the central laser pulse. Compared to other laser vortices, STOVs could prove more broadly useful for engineering applications.

Credit: Howard Milchberg

Powerful laser beams, given the right conditions, will act as their own lenses and "self-focus" into a tighter, even more intense beam. University of Maryland physicists have discovered that these self-focused laser pulses also generate violent swirls of optical energy that strongly resemble smoke rings. In these donut-shaped light structures, known as "spatiotemporal optical vortices," the light energy flows through the inside of the ring and then loops back around the outside.

The vortices travel along with the laser pulse at the speed of light and control the energy flow around it. The newly discovered optical structures are described in the September 9, 2016 issue of the journal Physical Review X.

The researchers named the laser smoke rings "spatiotemporal optical vortices," or STOVs. The light structures are ubiquitous and easily created with any powerful laser, given the right conditions. The team strongly suspects that STOVs could explain decades' worth of anomalous results and unexplained effects in the field of high-intensity laser research.

"Lasers have been researched for decades, but it turns out that STOVs were under our noses the whole time," said Howard Milchberg, professor of physics and electrical and computer engineering at UMD and senior author of the research paper, who also has an appointment at the UMD Institute for Research in Electronics and Applied Physics (IREAP). "This is a robust, spontaneous feature that's always there. This phenomenon underlies so much that's been done in our field for the past 30-some years."

More conventional spatial optical vortices are well-known from prior research--chief among them "orbital angular momentum" (OAM) vortices, where light energy circulates around the beam propagation direction much like water rotates around a drain as it empties from a washbasin. Because these vortices can influence the shape of the central beam, they have proven useful for advanced applications such as high-resolution microscopy.

"Conventional optical vortices have been studied since the late 1990s as a way to improve telecommunications, microscopy and other applications. These vortices allow you to control what gets illuminated and what doesn't, by creating small structures in the light itself," said the paper's lead author Nihal Jhajj, a physics graduate student who conducted the research at IREAP.

"The smoke ring vortices we discovered may have even broader applications than previously known optical vortices, because they are time dynamic, meaning that they move along with the beam instead of remaining stationary," Jhajj added. "This means that the rings may be useful for manipulating particles moving near the speed of light."

Jhajj and Milchberg acknowledge that much more work needs to be done to understand STOVs, including their physical and theoretical implications. But they are particularly excited for new opportunities that will arise in basic laser research following their discovery of STOVs.

"All the evidence we've seen suggests that STOVs are universal," Jhajj said. "Now that we know what to look for, we think that looking at a high-intensity laser pulse propagating through a medium and not seeing STOVs would be a lot like looking at a river and not seeing eddies and currents."

Eventually, STOVs might have useful real-world applications, like their more conventional counterparts. For example, OAM vortices have been used in the design of more powerful stimulated emission depletion (STED) microscopes. STED microscopes are capable of much higher resolution than traditional confocal microscopes, in part due to the precise illumination offered by optical vortices.

With the potential to travel with the central beam at the speed of light, STOVs could have as-yet unforeseen advantages in technological applications, including the potential to expand the effective bandwidth of fiber-optic communication lines.

"A STOV is not just a spectator to the laser beam, like an angel's halo," explained Milchberg, noting the ability of STOVs to control the central beam's shape and energy flow. "It is more like an electrified angel's halo, with energy shooting back and forth between the halo and the angel's head. We're all very excited to see where this discovery will take us in the future."

###

In addition to Jhajj and Milchberg, coauthors on the study include IREAP Associate Research Scientist Jared Wahlstrand and physics/IREAP graduate students Sina Zahedpour, Ilia Larkin and Eric Rosenthal.

The research paper, "Spatio-temporal optical vortices," Nihal Jhajj, Ilia Larkin, Eric Rosenthal, Sina Zahedpour, Jared Wahlstrand, and Howard Milchberg, appears in the September 9, 2016 issue of the journal Physical Review X.

This work was supported by the Defense Advanced Research Projects Agency (Award No. W911NF1410372), the Air Force Office of Scientific Research (Award No. FA95501310044), the National Science Foundation (Award No. PHY1301948), and the Army Research Office (Award No. W911NF1410372). The content of this article does not necessarily reflect the views of these organizations.

Media Contact

Abby Robinson
abbyr@umd.edu
301-405-5845

 @UMDRightNow

http://www.umdrightnow.umd.edu/ 

Abby Robinson | EurekAlert!

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

On the way to developing a new active ingredient against chronic infections

21.08.2017 | Life Sciences

Smart Computers

21.08.2017 | Information Technology

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>