title: Nondestructive high-resolution soft-boundary profiling based on forward shadow diffraction.
abstract: Nondestructive noncontact high-resolution optical technique for profiling soft or fluidic boundary of an opaque object is presented. Our technique utilizes the fact that the angle width, the angular separation between two adjacent intensity minima in the forward shadow diffraction, is inversely proportional to the projected width of the object in the same direction. An analytic formula for reconstructing the boundary shape is obtained for an object with two-fold symmetry in terms of the angle widths measured for various rotational angles of the object. The typical error in determining the object shape parameter is less than 0.2%, which corresponds to 20 nm of radial accuracy when applied to an object with a mean radius of 10 microns.
authors.affiliation: School of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: Songky
authors.initials: S
authors.lastname: Moon
authors.forename: Juhee
authors.initials: J
authors.lastname: Yang
authors.forename: Sang-Bum
authors.initials: SB
authors.lastname: Lee
authors.forename: Jeong-Bo
authors.initials: JB
authors.lastname: Shim
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Kim
authors.forename: Jai-Hyung
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyungwon
authors.initials: K
authors.lastname: An
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D008027:Light; D008422:Materials Testing / Q000379:methods*; D008962:Models, Theoretical; D012031:Refractometry / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013499:Surface Properties