Characteristics of evanescent polarization imaging

Abstract

A technique for obtaining native (uncrossed illumination/image polarizations) and induced (crossed illumination/ image polarization) using a significant amount of evanescent energy is described for a solid immersion lens (SIL) microscope. Characteristics of native and induced polarization images for different object structures and materials are studied in detail. Experiments are conducted with a NA ¼ 1.48 at ¼ 550 nm microscope. Near-field images are simulated and analyzed with an RCWT approach. Contrast curve versus object spatial frequency calculations are compared with experimental measurements. Dependencies of contrast versus source polarization angles and air gap for native and induced polarization image profiles are evaluated. By using the relationship between induced polarization and topographical structure, an induced polarization image of an alternating phase shift mask (PSM) is converted into a topographical image, which shows very good agreement with atomic force microscope (AFM) measurement. Images of other material structures include a dielectric grating, chrome-on-glass grating, silicon CPU structure, BD-R and BD-ROM.

Hyper-numerical aperture (NA = 28) microscope using λ = 156 µm femtosecond source for multi-photon imaging

“…The SIL, which was originally introduced by Mansfield and Kino [11], contains a mixture of evanescent and propagating waves at the sample surface [12,13]. To realize full resolution potential of a SIL, the object must be within the evanescent decay portion of the illuminating field.…”