Ultrashort pulses (~50-100 femtoseconds) from a titanium-sapphire laser are made up of many colors of light (~50-60 nanometers bandwidth). The duration of the pulse depends on how many colors there are and their spread in time. White light filamentation allows for the production of a large range of wavelength. Locking the phase of these wavelengths allows for the production of even shorter pulses.

Pulse-shaping is a technique in which the colors in an ultrashort pulse are manipulated in time. The pulse is split spatially into its different colors, then they are manipulated using a Spatial Light Modulator and recombined to produce a pulse which is shaped in time. My research interests currently include working on new pulse-shaper designs and working toward shaping pulses for white-light filaments.

Read more about filaments here.