Student research opportunities
Stable phase reference distribution over optical fibres
Project Code: CECS_525
This project is available at the following levels:
Engn4200
Please note that this project is only for undergraduate students.
Supervisor:
Bram SlagmolenOutline:
Next generation gravitational wave detectors, like Advanced LIGO, require a secondary arm length stabilisation scheme to assist in the lock acquisition of the full gravitational wave detector. Stabilisation is achieved via a secondary laser, which is injected in from the back of the 4 km long arm cavities. This second laser needs to be phase locked to the 200W science laser. To accomplish this lock, a small amount of light from the science laser is delivered to the two end-stations, using a single mode fibre. This light will provide the phase reference.
Environmental noise acting on the single mode fibre will degrade the phase stability of the light that is needed to phase lock the two lasers. A fibre phase noise cancellation scheme is needed to overcome this environmentally induced noise. The phase noise requirements are set to ~10 rad/rtHz < 1Hz to 1.5 mrad/rtHz at 1 Hz to 10 Hz, to enable the secondary laser to keep within tolerance of the science laser. This project will focus on the development of the noise cancellation scheme, to enable a stable phase reference for the secondary laser.
