Dwyer, SBarsotti, LChua, S S YEvans, MFactourovich, MGustafson, DIsogai, TKawabe, KKhalaidovski, ALam, P KLandry, MMavalvala, NMcClelland, D EMeadors, G DMow-Lowry, C MSchnabel, RSchofield, R M SSmith-Lefebvre, NStefszky, MVorvick, CSigg, D2016-05-112016-05-111094-4087http://hdl.handle.net/1885/101203Squeezed states of light are an important tool for optical measurements below the shot noise limit and for optical realizations of quantum information systems. Recently, squeezed vacuum states were deployed to enhance the shot noise limited performance of gravitational wave detectors. In most practical implementations of squeezing enhancement, relative fluctuations between the squeezed quadrature angle and the measured quadrature (sometimes called squeezing angle jitter or phase noise) are one limit to the noise reduction that can be achieved. We present calculations of several effects that lead to quadrature fluctuations, and use these estimates to account for the observed quadrature fluctuations in a LIGO gravitational wave detector. We discuss the implications of this work for quantum enhanced advanced detectors and even more sensitive third generation detectors.© 2013 Optical Society of AmericaKeywords: Advanced detector; Gravitational wave detectors; Of quantum-information; Optical measurement; Optical realization; Squeezed vacuum state; Squeezing enhancement; Third generation; Gravitational effects; Gravity waves; Noise abatement; Optical data processi2013-08-1210.1364/OE.21.0190472016-06-14