| dc.description.abstract | High-sensitivity accelerometers are a key technology in many applications including gravitational physics such as ground-based gravitational wave (GW) detectors [1], gravimetry measurements, vibration noise detection, inertial navigation systems, and many more. Highly sensitive inertial sensors that are commercially available are often large and incompatible with vacuum and cryogenic environments. The commercially available sensors that are compact in size face the issues of high acceleration noise floors. Fused silica has demonstrated high mechanical quality factors (Q) at room temperature, roughly 10˄7 . However at 110 K the Q drops to 10˄4 and at cryogenic temperatures (∼20 K) it drops even further to 10˄3 [2]. Silicon exhibits significantly better performance across both cryogenic and room temperatures, between 10˄7 and 10˄8 respectively [2, 3]. This is relevant for future ground-based gravitational wave detectors where cryogenic environments will be used to improve the sensitivity of the observatories [4, 5]. We will investigate compact millimeter-scale resonators made of silicon.
This thesis covers the development of compact optomechanical accelerometers optimized for frequencies at and below 1 kHz with comparable or enhanced acceleration noise floors. This includes the design, modeling, and fabrication of monolithic mechanical resonators, and their integration with laser interferometers to read out their test mass dynamics under the presence of external accelerations. | |
