Turbulence. It’s one of the leading causes of concern for anxious flyers. If you’ve ever flown, there’s a good chance you’ve been warned to fasten your seat belt or had a beverage spill as you’ve weathered a bumpy ride. But what if planes were equipped with a system that could detect turbulence from afar and automatically steer away from air currents ahead? Such a system, which relies on lidar, has been investigated by Airbus — and the results have been promising. Along with turbulence, lidar can also discriminate between volcanic ash and run-of-the-mill burning biomass in the atmosphere. While far less frequent than turbulence, volcanic ash can prove especially damaging to an aircraft’s engine. In 2010, the eruptions of the volcano Eyjafjallajökull in Iceland forced the cancellation of scores of flights, with large parts of the European airspace closed to traffic for days on end. Learn more in our cover story, “Onboard Lidar Detects Turbulence, Volcanic Ash Near and Far,” by Airbus’ Nikolaus Schmitt (read article). Elsewhere in the magazine: • Raman spectroscopy is unique in its ability to identify controlled substances and hazardous materials. A new Raman technique — see-through Raman — can measure samples beneath diffusely scattering packaging material. The advance could make it indispensable for hazardous material screening outside a traditional laboratory. See “Raman Spectroscopy Peers Through Packaging,” from B&W Tek (read article). • Diffractive optical elements are commonly found in medical and aesthetic lasers, as well as projection lighting. Recent enhancements in the manufacturing processes have now reduced undesired orders while simultaneously improving uniformity and achieving higher diffractive efficiencies. “Diffractive Optical Elements: Minimizing Zero Order,” from Holo/Or Ltd. (read article). • McPherson’s Erik Schoeffel details the use of a spectral test station for assessing diffraction grating efficiency at specific wavelengths in “Measuring Diffraction Grating Efficiency” (read article). • New findings in quantum superposition and quantum entanglement are leading to what some are calling a second quantum revolution. Contributing Editor Marie Freebody’s “New Frontier for Quantum Sensing” (read article). Finally, in this month’s special section, “Asia-Pacific: A Powerhouse Region,” Senior Editor Justine Murphy explores the increasing impact of APAC in the photonics market. She interviews Rich Mildren, a Future Fellow of the Australian Research Council and professor at Macquarie University, who shares insights on exciting photonics research in areas as diverse as astrophysics, quantum optics and nanophotonics. Enjoy the issue!