Abstract

Chirped dielectric mirrors are known to compensate the dispersive broadening of the ultrashort pulses: if different frequency components (different color components) of a pulse reflect at different depth of the mirror, the phase delays between these frequency components can be "repaired" in order to recover a nice ultrashort pulse’ such as it was before the dispersive broadening. We proposed and worked out a similar idea to compensate the diffractive broadening of the narrow laser beams upon reflection. We propose that particularly designed dielectric mirrors can in principle compensate that dephasing of the angular components of the beam. For example’ the modulated structure having an anolmalous dispersion [green area in Fig. 1a] can modulate diffractive broadening of the beam [Fig. 1b] and bring the beam to focus or image in reflection [Fig. 1c].

© 2015 IEEE