Measuring Scattered Light for LIGO Optics

Scattered light can adversely affect many types of optical systems. The Laser Interferometer Gravitational-wave Observatory (LIGO) seeks to detect astrophysical sources of gravitational waves using laser interferometery. Light scattered from LIGO optics degrades the astrophysical range of the detectors by reducing the shot-noise limited sensitivity through loss of laser power, and by adding non-stationary and non-linear noise terms to the detector output. The imaging scatterometer at CSUF is used to characterize light scattering from sample optics for Advanced LIGO and its future upgrades. This poster will describe the scatterometer apparatus and how it operates, and present the latest scatter measurements we performed.