Sensitivity enhancement of gravitational wave detectors via optomechanical interactions

A century after the prediction by Einstein and Schwarzschild ,gravitational waves (GWs) were directly detected for the first time by interferometric GW detectors. This discovery is the start of the era of GW astronomy. However, improved detector sensitivity is required to measure the vast number of weaker and more distant sources. The sensitivity of current detectors, such as LIGO, reached the quantum shot noise limit in the high frequency detection band. This thesis investigated theoretically and demonstrated experimentally sensitivity enhancement of GW detectors via optomechanical interactions and the three-mode parametric instabilities caused by these interactions.