By combining the merits of radiative cooling (RC) and evaporation cooling (EC), radiative coupled evaporative cooling (REC) has attracted considerable attention for sub-ambient cooling purposes. However, for outdoor devices, the interior heating power would increase the working temperature and fire risk, which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties. In this work, we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy. Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk, REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload, indicating a 12.0 °C lower temperature than the RC film under the same conditions in the outdoor experiment. In the nighttime with a low workload, RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime. In addition, our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise, thus mitigating fire risks. Thus, our design shows a promising solution for the thermal management of outdoor devices, delivering outstanding performance in both heat dissipation and flame retardancy.

Researchers at KAUST have unveiled a powerful way to tailor the lasing behavior of vertical-cavity surface-emitting lasers (VCSELs) using simple geometry changes. By reshaping the VCSEL cavity into non-circular geometries, they achieved unprecedented improvements in power, coherence, and polarization control. Their findings open new paths for high-speed communication, speckle-free imaging, sensing, and physical random number generation—without altering the core VCSEL fabrication process, offering a low-barrier route to advanced VCSEL-based technologies.

Lasers that emit extremely short light pulses are highly precise and are used in manufacturing, medical applications, and research. The problem: efficient short-pulse lasers require a lot of space and are expensive. Researchers at the University of Stuttgart have developed a new system in cooperation with Stuttgart Instruments GmbH. It is more than twice as efficient as previous systems, fits in the palm of a hand, and is highly versatile. The scientists describe their approach in the journal Nature. 

MIT physicists observed key evidence of unconventional superconductivity in magic-angle graphene. The findings could lead to the development of higher-temperature superconductors.

The research group led by Prof. Young-Jin Kim has demonstrated a nanometer-resolution displacement sensing methodology by actively modulating deep-UV beams generated via third-harmonic conversion of an 800 nm femtosecond laser. Instead of manipulating the deep-UV beam directly, the fundamental near-IR beam was pre-modulated and its phase profile was coherently transferred to the generated deep-UV harmonic, enabling stable and real-time control in an absorption-dominated wavelength region where conventional modulators do not operate. The team further realized high-visibility periodic beam patterns and tuned their pitch and orientation to induce moiré amplification against semiconductor periodic patterns, detecting displacement signals that were invisible to direct optical imaging. The demonstration provides a first practical route to active beam modulation-based precision metrology in the deep-UV band and is expected to extend toward EUV and X-ray regimes for future 3 nm node linewidth metrology, attosecond science, and real-time bio-imaging applications. This study has been published in PhotoniX (Q1, IF 19.1) on November 6 and supported by the National Research Foundation of Korea.