Talbot effect of a grating under ultrashort pulsed-laser illumination

The Talbot effect of a grating under ultrashort short-pulsed light illumina tion is analyzed from its Fresnel diffraction equation. We find that the ta lbot self-imaging effect gradually diminishes when the full width Delta tau at half maximum of the incident ultrashort laser pulse decreases. If Delta tau is within a few tens of femtoseconds, the self-imaging effect disappea rs. We note that the maximal value of the sharp peak of the intensity distr ibution at the first Talbot distance increases steadily along with the incr ease of Delta tau. Therefore, by using this phenomenon, the width of an ult rashort laser pulse can be measured roughly. (C) 2000 John Wiley & Sons, In c.