Incorporation of a FADOF to an ESPI system

摘要

Abstract: nic Speckle Pattern Interferometry (ESPI) has been used for many years in nondestructive testing applications in laboratories. Field applications of ESPI systems have been limited by the need to restrict the amount of light, sunlight and other sources, during operation. Interference filters and other techniques have been tried to increase the applicability of ESPI systems in daylight environments. Each of these attempts have been moderately successful. The FADOF (Faraday Anomalous Dispersion Optical Filter) is a revolutionary filter that improves throughput, field-of-view, and the signal-to-noise ratio of the laser signal returning from the test object. This paper describes the basics of a FADOF and how the filter can be incorporated into an ESPI system.!7