Keplerian beam expanderpdf

The distance between the two lenses in a Keplerian beam expander is equal to the sum of their focal lengths. If the focal lengths of the objective and eyepiece lenses are f1 and f2, respectively, then the distance d between the lenses is given by d = f1 + f2.

Keplerianvs Galileanbeam expander

A Keplerian beam expander is an optical device that uses two lenses to increase the diameter of a laser beam. It consists of a converging lens (objective) followed by a diverging lens (eyepiece), arranged in such a way that the beam passing through is magnified.

If the lenses are not placed at the correct distance, the beam expander will not function properly. The beam may not be collimated correctly, leading to a distorted or unfocused output. Proper alignment is crucial to ensure that the expanded beam remains parallel and well-defined.

Keplerian beam expanders offer several advantages, including a high degree of magnification and the ability to produce a collimated output beam. They are also relatively simple to design and can be used to improve the beam quality for various applications, such as in laser optics and scientific research.

The magnification factor of a Keplerian beam expander is determined by the ratio of the focal lengths of the two lenses. Specifically, the magnification M is given by M = f2 / f1. To adjust the magnification, you would need to change one or both of the lenses to ones with different focal lengths.