Gravitational wave detectors are in many ways the most sensitive instruments ever built and have opened a new window to the universe. The steadily growing number of discoveries helps us develop a better understanding of our cosmic setting and probe for exciting new fundamental physics.

Gravitational wave detection has reached the thermal noise limit of optical coating technology: Thermal effects in the mirror coatings drown potential signals in noise. This has sparked a broad search for novel coating materials, coating topologies, and mitigating technologies. One of the most promising avenues towards future gravitational wave detectors is the use of cryogenically cooled silicon mirrors and 2µm wavelength lasers.

Your goal in this project is to optimise the coupling efficiency of a laser into an optical resonator formed by two or more mirrors for a coating noise experiment. You will have to analyse and optimise the spatial laser beam profile and investigate the overlap of optical modes with mechanical eigenmodes of the mirrors. Different higher order modes sample the thermal fluctuations of mirror substrates and coatings differently and offer a way to directly measure the coating thermal noise that is limiting kilometre-scale gravitational wave detectors.

The Centre for Gravitational Astrophysics offers a collaborative, diverse, and supportive research environment across the full breadth of gravitational wave discovery. The Centre is a joint effort of RSAA and RSPhys, and hosts a node of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav).

A working knowledge with optics and lasers is recommended. Computational and programming skills (e.g. Python, MATLAB, Finite Element Analysis) are preferred. The project scope can be adjusted according to student level.