It is especially useful for determining the degree of beam divergence of real laser beams and the minimum focussed spot size.

The beam divergence of a laser beam is a measure for how fast the beam expands far from the beam waist.

A large beam divergence for a given beam radius corresponds to poor beam quality.

A low beam divergence can be important for applications such as pointing or free-space optical communications.

For the optical regime, see beam divergence.

The beam divergence makes it necessary to be as near as possible.

This type of beam divergence is observed from optimized laser cavities.

To adjust for beam divergence a second car on the linear stage with two lenses can be used.

Light from certain types of laser has the smallest possible beam divergence.

Increasing the beam divergence.