New Sensor Uses Slowed Light To Detect The Gravitational Pull Of Tiny Objects

Phys.org Science•Published: Oct 12, 2026 05:30 PM IST

Researchers at Shanghai Jiao Tong University have developed a groundbreaking sensor capable of detecting the gravitational pull of millimeter-sized objects. By integrating a torsion pendulum with an optical microcavity, the team successfully measured minute gravitational forces that were previously nearly impossible to detect.

Stopped Light Behavior: The sensor utilizes a coupled photon-phonon resonance that significantly slows light pulses, creating a more pronounced optical response to tiny physical movements.
High Sensitivity Levels: The device achieves an acceleration sensitivity of 3.06 × 10⁻¹⁶ g, allowing for the detection of gravitational force changes as small as 3.02 × 10⁻¹⁶ N.
Innovative Architecture: The system combines a suspended torsion pendulum with an optical microcavity, which converts nanoscale displacements into measurable optical signals.

The Context & Background

This development addresses the long-standing challenge of measuring gravity at microscopic scales, where the force is notoriously weak. The breakthrough provides a new tool for physicists to investigate the intersection of gravity and quantum mechanics.

Why it matters:This technology bridges the gap between classical gravity and quantum physics, potentially unlocking new ways to study the fundamental nature of the universe. By enabling precise measurements of microscopic gravitational fields, it paves the way for advanced sensors and a deeper understanding of how quantum states influence gravity.

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