Distortion Correction for an Imaging Ellipsometer.

A simple imaging add-on utilizing the combination of a relay lens and an optical grating to a nulling ellipsometer for the purpose of imaging and correcting angular distortion is designed, built, and tested. Image contrast is achieved on a standardized silicon wafer, graphene transferred on silicon wafer, a self-assembled monolayer of 1-octadecanethiol on gold, and a 1:1 mixture of dilauroylphosphatidylcholine / distearoylphosphatidylcholine (DLPC/DSPC) on copper. The configuration used in this paper corrects the angular distortion and depth of focus with a spatial resolution of 4.38 μm in the laser's incident direction and 7.81 μm in the direction that is perpendicular to the incident plane together with 3 Å of normal resolution while still maintaining a large field of view of at least 720 μm × 550 μm in focus without executing any line scanning, post-image reconstruction, or specially customized objective method. Better resolution is possibly attained with higher NA optics.