Abstract:
Designs based on single diffractive-optical-elements for obtaining flat-top laser
intensity distributions that remain constant over a long range during free-space propagation are
presented. Flat-top beams with different orders n exhibit a different range of propagation. For
various working distances z, the resulting flat-top beam yields a different depth of focus. By
controlling spectral properties of laser distributions, it is possible to maintain invariant flat-top
intensity distributions for relatively long propagation distances.
