Numerical characterization of focused ultra-short Gaussian light pulses
Abstract
Focal patterms of focused ultra-short Gaussian pulsed beams are compared to the corresponding profiles with focused continuous wave (CW) beams with wavelength equal to the central wavelength λ0. Focal profiles differ from that with CW in terms of beam spot size and peak locations as a function of the pulse width (Δτ) and numerical aperture (NA). Effectively broadened axial and transverse profiles are noted with pulsed beams. Intensity distributions also reveal presence of other colors aside from that corresponding to λ0. There is a trade-off between achieving high peak power for the pulse and the amount of energy of λ0 critical to excitation application. As Δτ is increased beyond ~100 fs, the patterns approach that with CW, thus differences will only be apparent for Δτ < 10 fs.