Compact Sensing

  • We create inertial sensors by using displacement interferometry techniques to measure motion of our low resonance monolithic resonators.
  • Objective : Develop a field deployable gravimetric sensor (able to measure gravity at a point on earth’s surface) that is precise, reliable, compact, and relatively lightweight..
  • Working:
  • It utilizes laser interferometers to measure the displacement, or change in position relative to an arbitrary starting point.
  • Resonators oscillate in one constrained direction, and can be viewed as a test mass on the end of a spring.
  • When the direction of motion is aligned downward, gravity can act on the mass in the measurement direction. When gravity levels change, the pull gravity exerts on the test mass changes. In times of increased gravity, the test mass will be pulled lower, and when gravity decreases the test mass will rise up.
  • Measuring this change in relative position using displacement interferometry, we can determine the acceleration due to gravity.

Displacement Interferometer

Results obtained :

  • LASSO has demonstrated the concept of creating inertially sensitive systems in this manner before, but the current goal is to make the system more compact.
  • The current interferometer uses large optical components which are in turn mounted to the optical table. This uses a lot of space and allows noise to enter the measurements through vibrations in each separate element.
  • Current research: It is focused on utilizing compact prism optics mounted on the frame of the resonator. This will decrease both the size and noise associated with the sensor, leading to an improved, compact system.