Synopsis: Let a Thousand Lasers Shine

Thousands of coupled lasers offer a new way to study how frustrated systems behave.

From water molecules in ice to spins in magnetic materials, physical systems are sometimes spoiled for choice. This can occur if, out of many configurations, no single ground-state arrangement is favored. Such frustrated systems have been invoked to explain a number of physical phenomena, including magnetic monopoles, high-temperature superconductivity, and the fractional quantum Hall effect, so researchers have sought to create model systems to test out ideas about frustration with complete control. In Physical Review Letters, Misha Nixon and colleagues at the Weizmann Institute of Science, Israel, report experiments with more than a thousand individual laser beams in a single optical resonator in which controllable coupling can produce more realistic forms of frustration for further study.

The researchers placed a mask containing thousands of tiny holes between the mirrors of an Nd:YAG laser. Each aperture defined a separate laser path, and different arrangements of the holes established different lattice patterns: hexagonal, triangular, or the kagome “basket weave.” By changing the position of the laser cavity output mirror, the authors could couple the lasers together by allowing light to leak from one laser to its neighbors. As the lasers go in and out of phase, patterns of optical interference change in the laser output. This allowed the authors to reproduce the frustration phases seen in the well-known $X\phantom{\rule{0}{0ex}}Y$ model of spins, as well as absence of long-range order found in frustrated systems and its removal by introducing next-nearest-neighbor coupling. – David Voss

More Features »

Announcements

More Announcements »

Optics

Previous Synopsis

Interdisciplinary Physics

Nanophysics

Related Articles

Optics

Focus: Vortices of Light on the Cheap

A simple laser setup has spontaneously produced nonuniform polarization patterns called vector vortices. Read More »

Plasma Physics

Viewpoint: Free-Electron Laser Does the Twist

Researchers have used a free-electron laser to produce vortex radiation at extreme-ultraviolet wavelengths. Read More »

Biological Physics

Focus: Bacteria Form Waveguides

A laser beam sent through a suspension of marine bacteria pulls the organisms into the beam, which focuses the light. Read More »