NIST has developed a new type of accelerometer that uses laser light instead of mechanical strain to measure acceleration. The optomechanical accelerometer is just a millimeter thick and operates over a wider range of frequencies than existing devices. It provides higher accuracy in measuring acceleration and doesn’t require calibration.
The device works by measuring the change in distance between two highly reflective surfaces using a stable single-frequency laser. An optical frequency comb is used to measure the cavity length with high accuracy. The proof mass and supporting beams are designed to behave like a simple spring or harmonic oscillator, enabling low measurement uncertainty over a wide range of acceleration frequencies.
The optomechanical accelerometer can detect accelerations as tiny as 32 billionths of a g and has higher sensitivity than all accelerometers on the market with similar size and bandwidth. With further improvements, it could be used as a portable, high-accuracy reference device to calibrate other accelerometers without needing to bring them into a laboratory.
Source: https://www.nist.gov/news-events/news/2021/03/better-way-measure-acceleration
Keywords: accelerometer, optomechanical, resonant, wavelength, frequency
