Bandwidth-limited pulse

Optical pulses of this type can be generated by mode-locked lasers.

For different pulse shapes, the minimum duration-bandwidth product is different.

A bandwidth-limited pulse can only be kept together if the dispersion of the medium the wave is travelling through is zero; otherwise dispersion management is needed to revert the effects of unwanted spectral phase changes.

For example, when an ultrashort pulse passes through a block of glass, the glass medium broadens the pulse due to group velocity dispersion.

Keeping pulses bandwidth-limited is necessary to compress information in time or to achieve high field densities, as with ultrashort pulses in modelocked lasers.