Improving the sensitivity of gravitational-wave detectors

Since the start of their first observing runs in fall 2015, Advanced LIGO and Virgo have made direct detections of gravitational waves created by the collisions of black holes and of neutron stars, thus bringing to life a new instrument for astronomy. This is accomplished through their measurements of infinitesimal changes (less than 10^-19 m at 100 Hz!) in the distance between two largely separated mirrors.

The Advanced LIGO laser interferometers are already the most precise measurement devices in the world, but there nonetheless remain many challenges along the path to further improve the interferometers in order to increase the signal-to-noise ratio and rate of gravitational wave detections. Noise resulting from fundamental physics such as the quantum nature of light and from technical sources such as the imperfect sensors used for controlling the interferometer's myriad degrees of freedom require clever solutions that push the limits of technology.

There are several possible research directions for a PhD student. Projects could include developing and testing new interferometric readout schemes, researching new laser wavelengths, designing and building tilt-insensitive inertial sensors for improved seismic isolation, improving the integration of squeezed light to the interferometers, designing and prototyping new optical layouts for sensitivity improvement at targeted frequencies, modelling control topologies for third generation interferometers such as the Einstein Telescope, and contributing to fundamental physics experiments using precision interferometry. The PhD student will gain skills in high-precision optical experiments and noise analyses of complex experimental systems, all the while contributing to the budding field of gravitational-wave astronomy.