Upgraded FSI

We have upgraded a commercial Frequency Scanning Interferometry (FSI) system (supplied by Etalon) with an optical amplifier. This allowed us to demonstrate reflectorless FSI operation with a variety of surfaces. We found that successful reflectorless FSI operation depends on the interplay of surface quality (specular vs diffuse reflection), beam spot size on the object, distance of the collimator to the object, and the angle of incidence for specular reflection. This report summarises out findings on how to achieve reflectorless FSI operation under different conditions.