Answer:
The fundamental resolution of an optical instrument is set by the wave nature of light.
Explanation:
According to quantum mechanics, light acts both as a particle and a wave. However, the fundamental resolution of an optical instrument, such as a lens, is limited due to the acting of light as a wave.
In particular, the resolution of an optical instrument is limited by the diffraction effect, which is a phenomenon of waves. Consider for example a convex lens which we are using to observe an object.
The light coming from a point of the object reaches the lens, and it diffracts, forming a diffraction pattern called Airy disk. Another point in the object, adjacent to the first one, also makes diffraction in the lens: the two points can be distinguished through the lens only if their separation is larger than the radius of the Airy disk. Mathematically, the two points can be resolved (distinguished) if their angular separation is larger than
[tex]\theta=1.22 \frac{\lambda}{D}[/tex]
where
[tex]\lambda[/tex] is the wavelenght of light
D is the diameter of the lens aperture
Therefore, this is basically the fundamental resolution of the lens, and we see that it is affected by diffraction, which is a phenomenon of waves.
