Laser power stabilization via radiation pressure
This experiment is about a new radiation pressure based scheme to sense and stabilize the power fluctuations of a laser beam.
The novel aspect of the scheme is that the power fluctuations are sensed via the radiation pressure driven motion they induce on a micro-oscillator mirror (like the one displayed in the picture).
The mirror position and its fluctuations are determined by means of a Michelson interferometer, which is the in-loop sensor for this scheme. This technique exploits a similar concept to a nondemolition measurement, since the power fluctuations are inferred by measuring the fluctuations in the phase observable of the beam in the interferometer.
This process results in higher in-loop signals for power fluctuations than what would be achieved by a direct detection, e.g. via the traditional scheme where a fraction of the laser power is picked off and sensed directly by a photodetector. Another remarkable advantage of this scheme is that it enables the generation of a strong bright squeezed out-of-loop beam.
This technique is a promising step towards an improved stabilization scheme to be used in the future generation of gravitational wave detectors and also in optomechanics experiments.
This project is a collaboration between the AEI, the group of Thomas Corbitt in the Louisiana State University, the group of Stefanie Kroker at TU Braunschweig/PTB, and the group of Christian Scheffler at the Fraunhofer IOF.