Principle

Optical devices are used to discern objects which are very far
away or very small. Essentially, these instruments are designed to
enlarge the visual angle. Whether this alone is sufficient to
visualize the object depends on various factors, which the students
should investigate.
Each ray emitted from an object point (point light source) is
diffracted in the tube of the optical instrument. In this
experiment, the two slits of a double slit represent the light
sources (objects). Two diffraction peaks of 0th order are created,
which can just be distinguished from each other when Rayleigh’s
Criterion is fulfilled. This criterion states that the distance
between the diffraction peaks of 0th order may not be smaller than
half of the distance between the diffraction troughs of 1st order
(comp. Fig. 24).

Benefits


Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench

Extension with others sets at anytime, no additional light sources needed, recognition value for students



Tasks

On which factors does the resolving power of optical devices
depend? In a first experiment the conditions are
investigated under which two objects (object points) can just
still be perceived individually, i.e. resolved, with the aid of an
optical device. Afterwards, the validity of Rayleigh’s Criterion
d = 1/2 · d1 (comp. Fig. 24) for the resolving power
of optical instruments is verified.