A nonrepeating laser, a two-way phase surface and a quantum engine shrink wave control
A new surface reads optical phase in both directions, a nonrepeating photonic crystal lases at room temperature, and a superconducting circuit turns heat into work. Complex wave control is moving into smaller devices.
Science··Evening
A laboratory metasurface that reads phase in two directions
Quantitative phase microscopy images transparent cells without staining, but measuring the phase gradient in two perpendicular directions has meant taking separate images or moving parts. According to Medical Xpress, a nonlocal metasurface reported in Nanophotonics does both in one shot using wavelength multiplexing. The device processes the whole image rather than ray by ray, so it can sit directly in front of the sample instead of needing a long optical path, and it folds in differential phase contrast to hold down noise. Ann Roberts and doctoral student Haiwei Wang led the work with RMIT and Melbourne at the ARC Centre of Excellence for Transformative Meta-Optical Systems. It remains a laboratory prototype: it needs a tunable infrared laser across precise wavelengths, supporting hardware is expensive, and patterns are still written by electron beam. The team points to nanoimprint lithography as the route to volume, and names point-of-care diagnostics, endoscopes and telescope wavefront sensing as targets. Bringing both phase axes onto one thin surface shortens the optical path, removes moving parts and fits complex wave measurement into a smaller instrument slice.[1]
Room-temperature lasing on a pattern that never repeats
Photonic-crystal surface-emitting lasers normally rely on a repeating lattice of etched holes. According to Phys.org, a team at the University of Illinois Grainger College of Engineering reports in Applied Physics Letters a quasi-periodic version built on a buried dielectric layer instead. Graduate student Erin Raftery etched a silicon dioxide layer and grew semiconductor over it, producing the refractive-index contrast without the vertical hole etching the usual design needs. Dropping that constraint allows a pattern that never repeats: the structure can be drawn rather than tiled, which in principle opens emission wavelength and beam shape to tuning. The device lased at room temperature. Electrical injection has not been demonstrated yet, and Kent Choquette's group frames the result as a physics demonstration, with the road to a manufacturable laser still ahead. Like the metasurface that reads phase on two axes, this laser pulls wave control out of a thick optical stack into a thin, patterned layer. One shrinks measurement and the other shrinks emission; both remain laboratory stages and do not promise a field product.[2]
A superconducting Otto cycle turns heat into work
According to ScienceDaily, drawing on an Aalto University release, researchers coupled a transmon qubit to a resonator and a quantum-circuit refrigerator, then drove the qubit through a cyclic Otto cycle inside a cryostat. Measurements showed that heat passing through the qubit produced positive work. The same refrigerator supplies both the hot and the cold environment, tuned on demand by control pulses, so the device does without two separate baths. Tuomas Uusnäkki is first author and Mikko Möttönen led the work, published in Nature Communications. Möttönen frames the target as autonomous read-out hardware: by 2035, Finland's quantum strategy envisages 1,000 logical qubits, which with current technology would mean millions of microwave cables that each cost about a thousand euros and inject noise. The circuit was fabricated at OtaNano, Finland's national nano and quantum research infrastructure. A thin surface that reads phase, a laser on a nonrepeating pattern and a superconducting cycle that turns heat into work move wave and energy control into smaller devices with fewer parts and shorter paths. Each is a measured laboratory step and has yet to open a product line. Complex wave control is now being rebuilt at the scale of metasurfaces, photonic crystals and superconducting circuits as well as on large optical benches.[3], [1], [2]
