The atmosphere is not a perfectly uniform or stationary medium. Changes in temperature, airflow, and air density continuously alter the refractive index of air, creating atmospheric turbulence. When a laser beam travels through such an environment, it may wander, distort, spread, or flicker, causing its originally concentrated energy to become unstable. These effects can reduce the reliability of free-space optical communication, LiDAR, remote sensing, and long-distance energy delivery. In this study, the researchers addressed this challenge from two complementary directions. The first was to improve the mathematical description of atmospheric turbulence so that numerical simulations could more accurately predict laser propagation under real-world conditions. The second was to identify beam types that are naturally more resistant to turbulence, thereby improving system stability at the source.

Light detection and ranging (LiDAR) has become indispensable for high-speed three-dimensional sensing in applications ranging from autonomous vehicles to drone surveillance. Among various LiDAR technologies, time-stretch LiDAR stands out for its ability to perform parallel detection using a single broadband pulse. By dispersing different wavelength components in both time and space, it creates hundreds of independent detection channels at once, offering a route to high frame rate, single-pixel 3D imaging without mechanical scanning. Yet this concept faces two fundamental obstacles when applied to complex real-world scenes. First, to measure distance with high precision, each spectral channel must contain enough longitudinal modes to generate a sufficiently short pulse. This consumes spectral bandwidth, which directly reduces the total number of available channels. This is an intrinsic trade-off between resolution and channel count. Second, when targets have varying depths, different channels return echoes with different delays. This disrupts the designed frequency-to-time mapping, causing adjacent channels to interfere with one another. Such crosstalk introduces ranging errors and imaging artefacts. Conventional solutions, such as assigning dedicated transmitter-receiver pairs per channel or introducing large dispersive delays between channels, either make the system bulky and complex or further sacrifice the number of channels. A fundamentally different approach has long been needed.

Thermal and mechanical signals are two of the most fundamental physiological cues, reflecting thermoregulation, tissue status, and body motion. Their simultaneous monitoring is essential for a broad range of applications, including wearable healthcare, rehabilitation, human–machine interaction, and soft robotics. Driven by the rapid development of flexible electronics, multifunctional wearable sensors capable of monitoring multiple physiological parameters have attracted increasing attention. Compared with conventional rigid devices, flexible sensors can conform intimately to the skin, enabling continuous, comfortable, and long-term physiological monitoring for next-generation digital healthcare.

Researchers from the Military University of Technology in Poland and the Czech Academy of Sciences have demonstrated exactly that by developing a new type of all-optically tunable 3D photonic crystal based on Blue Phase liquid crystals. Unlike conventional liquid crystals, Blue Phases are remarkable because they self-assemble (their molecules spontaneously organize) into a highly ordered 3D structure with a periodicity comparable to the wavelength of visible light. This unique architecture allows them to selectively reflect specific colors, effectively making them 3D photonic crystals and an attractive option for advanced optical technologies. The relevant research was recently published in Photonics Research, Volume 14, Issue 8, 2026. [Eva Oton, Martin Cigl, Przemysław Morawiak, Karel Pomeisl, Sergei Mironov, Wiktor Piecek, Alexej Bubnov, "Optical tuning of a 3D blue phase photonic crystal with chiral photosensitive dopants," Photonics Res. 14, 3437 (2026)]