New chip-scale gyroscope measures rotation with unprecedented sensitivity

Researchers have developed a tiny optical gyroscope that can detect rotation as slow as 37 degrees per hour, representing a nearly 2000-fold improvement over previous versions. This groundbreaking technology could revolutionize precision navigation and orientation systems, especially in scenarios where GPS signals are unavailable.

Gyroscopes are devices that measure an object's rotation, helping determine its orientation and movement. While chip-based gyroscopes are commonly found in smartphones, they typically have limited sensitivity, rendering them unsuitable for demanding applications.

The new chip-scale gyroscope is based on a special type of low-noise laser made using silicon nitride waveguides. It combines advanced technologies to achieve high sensitivity in a compact form factor, making it compatible with standard CMOS chip-processing methods and requiring only a minimal amount of optical power. The device's sensitivity is made possible by a silicon nitride ring-shaped optical circuit, which encloses light in a large area, resulting in extremely selective filtering and minimal photon loss.

The researchers behind this innovation are from the University of California, Santa Barbara, and the California Institute of Technology. Their work involves combining a Brillouin laser gyroscope approach with a Brillouin laser-on-a-chip based on a silicon nitride platform. The key to this breakthrough lies in the use of a high-quality (Q) factor microresonator, which allows light to circulate many times, making the device extremely sensitive to rotational changes.

In practical terms, when the chip is stationary, two semiconductor lasers send light into the ring in opposite directions. When the chip rotates, even a tiny change in frequency between the two light signals occurs, which the gyroscope can detect and use to measure the rotation rate. The researchers' tests demonstrated that the gyroscope can measure rotations as small as 37 degrees per hour, highlighting the potential of this technology for high-precision sensing in applications such as cars, aircraft, and spacecraft.