Locking in on gravitational waves

An active control system is required to bring the suspended optics of the interferometer at its working point and maintain it there, i.e. to keep the distance between the mirrors constant and measure the GW-induced length fluctuations. At present, this lock acquisition can only start when the optics are pre-aligned. For large misalignments human action is involved. This Mikroniek article introduces a new way of auto-aligning largely misaligned suspended optical systems. (Image courtesy of Rob Walet)