The Glasgow 10 m prototype laser interferometric gravitational wave detector

We present a description of the prototype interferometric gravitational wave detector at Glasgow. The detector, which has been under development for a number of years, consists of two perpendicular 10-m-long high finesse Fabry–Perot cavities formed between test masses hung as pendulums and is illuminated with a cw argon ion laser. The differential displacement sensitivity of the detector is ∼7×10−19 m/√Hz from 500 Hz → 3 kHz and is close to being limited by photoelectron shot noise in the detected photocurrent.