Answer to Question #90070 in Optics for Shivam Nishad

Question

What do you understand by resolving power of a microscope ? Show that for a microscope, the smaller the numerical aperture (N.A) the greater will be the resolving power.

Answer 1

The resolving powers is about how deep we can see our world. Light microscopes let us distinguish objects as small as a bacterium. Electron microscopes have much higher resolving power – the most powerful allow us to distinguish individual atoms. But in this case we can not see atoms in usual sense. We see only responce of atoms and build the probability picture for atom coordinates.

The larger the N.A., the higher the resolving power because we have Resolving Power Formula:

$$\varepsilon=0.61 \cdot \frac{\lambda}{N.A.},$$

where $\lambda$ is a wavelength, $N.A.$ is objective lens N.A.