Impact of localized defects in light scattered by optical components: measurement and analysis

Defects and contaminants can be a critical source of performance loss. This paper presents and demonstrates the capabilities of a new SPatially and Angularly Resolved Scatterometry Equipment (SPARSE) designed to measure spatially resolved ARS of optical surfaces. Besides a calibration sample, the measurement results of three samples are detailed here. They show the amount of information accessible from a measurement, including the ability to distinguish between roughness, localized defects, and scratches. The scattered light generated by each of these three types of defects can be quantified independently.