Question

(1 point) READING 4 The resolution of a microscope is diffraction limited, just as the eye, but gains a significant advantage because an object can be placed very close to its objective lens. The smallest resolvable linear separation xTor an ordinary light microscope is: where λ is he wavelength o light used, and Θ ls he half Viewing angle 0 he obiective The quantity n sne s ca e the num enca aperture of he obiective where n s the inf X ofre action. The minimum resolvable separation of two objects can be reduced by placing a liquid with a large index of refraction between the object and the objective, as in an oil immersion microscope [14] Image: Microscope Coarse locus Fine focus Srage Light source This picture was found at the followng webste: htm [14] F. R. Hallett, P. A. Speight, R. H. Stinson, INTRODUCTORY BIOPHYSICS (New York: John Wiley & Sons, 1977) With light of wavelength 500 nm and a lens with a numerical aperture or 0.5, what is the minimum resolvable separation of two objects? micrometers

Answer 1

The smallest resolvable distance is,

2(NA)

Substituting values we get,

= 500 × 10-9 m = 0.5 μm 2(0.5)

Hence the minimum resolvable separation is 0.5 micrometers.