Realizing a true Bessel beam would thus require infinite power.
A true Bessel beam is created by interfering (in 2D) two plane waves, see https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Be.... You can see in the image that the "Bessel beam" area is bounded, it is the conical shape where the beams overlap.
The radial intensity distribution of a Bessel beam is described by Bessel functions, which are not square integrable (integral is not finite), see https://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Be....
Realizing a true Bessel beam would thus require infinite power.
A true Bessel beam is created by interfering (in 2D) two plane waves, see https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Be.... You can see in the image that the "Bessel beam" area is bounded, it is the conical shape where the beams overlap.
> What is an example of a "bounded" beam?
A "standard" Gaussian laser beam, see https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/La...