Intensity profile of chirped polychromatic laser in an apertured system

Propagation expression of chirped polychromatic laser in an aperture system is deduced in our investigation. Influences of the chirp parameter and the aperture width on the intensity profile of the chirped polychromatic laser are studied and illustrated by numerical calculation. The results showed that intensity of the wave rear presents spreading effect but that of the wave front presents narrowing effect. Namely, the intensity distribution spreads with decreasing the aperture width and increasing the chirp parameter in the wave rear whereas it tends to concentrate with increasing the chirp parameter in the wave front. A physical explanation based on a simplified representation indicated that the influence of the chirp parameter on the intensity was determined not only by its quantity but also by the sign of the local time.

► The propagation expression of chirped polychromatic laser in an aperture system is given.
► The intensity profiles depend on the chirp parameter and the aperture width.
► The intensity profiles present not only spreading effect but also narrowing effect.
► The sign of the local time determines the influence of the chirp on the intensity.