Optical Trap

Longitudinal and Angular Optical Trap of a Gram-Scale Mirror

Optical trap

The LIGO detectors are held in lock and alignment using optical error signals and magnetic actuation on the test masses. Angular control is limited by sensing noise in the feedback loops. It is possible to keep cavities locked passively using optical springs (optical traps). This will eliminate active angular controls and the associated sensing noise. The Syracuse University Gravitational Wave Group is constructing an optical trap to stabilize a mirror in the length and angular degrees of freedom. The trap can also become a testbed to study quantum mechanics on macroscopic objects. The experiment is based on two in-vacuum suspended optical cavities which have a single mirror in common. The radiation pressure of the light in the two cavities will damp the motion of the common mirror.