Ultrafast lasers emit pulses lasting only a few hundred femtoseconds (quadrillionths of a second). These flashes of light power applications from precision micromachining to eye surgery to optical frequency combs, the Nobel Prize-winning technology behind today's most precise optical atomic clocks. Yet despite more than two decades of effort, ultrafast lasers have largely remained bulky, expensive systems confined to optical tables.

In nature, there exist structures that are mirror images of each other but cannot be perfectly superimposed. These are known as chiral objects, derived from the Greek word for "hand," since left and right hands share the same relationship. Although similar in structure, chiral molecules exhibit different behaviors, and chirality is central to life itself. DNA has a twisted chiral structure, and living organisms prefer one handedness over the other. This distinction is equally important in drug design, materials science, and nanotechnology.

By definition, elementary particles can't be broken into smaller pieces. But in a new theoretical study published in Physical Review Letters, Johannes Skaar and colleagues have revealed what would happen if you tried anyway for a single photon. The answer is deeply strange: attempting to cut a photon in two wouldn't produce two smaller photons, but instead conjure an infinite number of them out of thin air.

Laser systems operating in the 2-micrometer wavelength range open diverse opportunities in medical technology, agriculture, and plastics processing. In the Eurostars project DECOMP, Laser Zentrum Hannover e.V. (LZH) has developed novel fiber optic components that overcome previous technical barriers.

Quantum entanglement is a state in which particles are entwined with each other. In this entwined state, the properties of one particle influence the other, even when they aren't physically close to each other. This phenomenon has often been observed in small quantum systems with only a few particles in them, where researchers can use it to store and process quantum information. Rice University professor Qimiao Si is interested in understanding and applying quantum entanglement to macroscopic systems with vast numbers of particles.