Ученые создали плоскую оптическую нить для сверхчувствительных датчиков

A New Take on Optical Fiber Optical fibers are widely used to transmit information, but their potential goes far beyond communications. Researchers have now developed an unusual flat optical fiber that could make fiber-based sensors far more sensitive. The technology, described in a study published in Nature Communications, uses a specially designed fiber with a flat, quadrilateral shape rather than the traditional circular cross-section. Researchers call it a high-aspect-ratio flat fiber, or HARFF. Its unusual geometry allows the fiber to respond strongly to mechanical and environmental changes. Designed for Greater Sensitivity The researchers created the fiber using a stack-and-draw manufacturing process. This technique allows them to produce long sections of specialized glass fiber while maintaining its distinctive shape. The flat structure gives engineers greater control over how the fiber reacts when pressure or other forces are applied. The fiber can undergo controlled deformation, producing measurable changes in its optical properties. One important property is birefringence, which describes how light behaves differently depending on its polarization. Changes in the fiber’s physical state can alter this optical response, allowing sensors to detect very small variations in their surroundings. Pressure and Temperature Detection Tests showed that the new fiber can provide exceptionally strong pressure responses. The researchers reported pressure sensitivity that can reach levels roughly 1,000 times greater than those of comparable conventional fibers. The team also demonstrated temperature sensing by incorporating a metal alloy into an internal channel of the fiber. As temperature changes, the alloy expands or contracts and produces mechanical stress within the surrounding glass. The resulting optical change can reveal variations in temperature. Potential for Future Sensors The technology could find applications in structural monitoring, aerospace systems, industrial machinery, robotics, and other environments where precise measurements are important. Although the flat optical fiber remains a research-stage technology, its highly tunable design could offer engineers a new way to build compact and sensitive sensors. The study shows that simply changing the geometry of an optical fiber can dramatically expand what it can detect.