Large temporal front distortion of femtosecond pulses occurs in lenses having chromatic aberration. The effect is due to the difference between the phase and group velocities. Equations describing the pulse-front delay in singlet lenses, achromats, and compound lenses are presented. The pulse-front delay is several orders of magnitude larger than the broadening caused by group-velocity dispersion in the lens material. Delays occurring in Fresnel-type zone plates are also described.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics