Dependence of transverse and longitudinal resolutions on incident Gaussian beam widths in the illumination part of optical scanning microscopy.
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.
Chon
Hyung-Su
HS
School of Physics, Seoul National University, Seoul, Korea.
Park
Gisung
G
Lee
Sang-Bum
SB
Yoon
Seokchan
S
Kim
Jaisoon
J
Lee
Jai-Hyung
JH
An
Kyungwon
K
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