title: Dependence of transverse and longitudinal resolutions on incident Gaussian beam widths in the illumination part of optical scanning microscopy.
abstract: We studied both theoretically and experimentally the intensity distribution of a Gaussian laser beam when it was focused by an objective lens with its numerical aperture up to 0.95. Approximate formulas for full width at half-maximum (FWHM) of the intensity distribution at focus were derived for very large and very small initial beam waists with respect to the entrance pupil radius of the objective lens. In experiments, the energy flux through a 0.5 microm pinhole was measured for various pinhole positions. It was found in theoretical analysis and confirmed in experiments that the FWHMs at focus in the transverse and longitudinal directions do not increase much from the ultimate FWHMs until the input beam waist is reduced below half of the entrance pupil radius.
authors.affiliation: School of Physics, Seoul National University, Seoul, Korea.
authors.forename: Hyung-Su
authors.initials: HS
authors.lastname: Chon
authors.forename: Gisung
authors.initials: G
authors.lastname: Park
authors.forename: Sang-Bum
authors.initials: SB
authors.lastname: Lee
authors.forename: Seokchan
authors.initials: S
authors.lastname: Yoon
authors.forename: Jaisoon
authors.initials: J
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; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008027:Light; D008029:Lighting / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods*; D015233:Models, Statistical; D016011:Normal Distribution; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity