High localization, focal depth and contrast by means of nonlinear Bessel beams.
We show an experimental and computational comparison between the resolution power, the contrast and the focal depth of a nonlinearly propagated diffraction-free beam and of other beams (a linear and a nonlinearly propagated Gaussian pulse): launching a nondiffractive Bessel pulse in a solution of Coumarine 120 in methanol creates a high contrast, 40 mm long, 10 microm width fluorescence channel excited by 3-photon absorption process. This fluorescence channel exhibits the same contrast and resolution of a tightly focused Gaussian pulse, but reaches a focal depth that outclasses by orders of magnitude that reached by an equivalent Gaussian pulse.
Polesana
Paolo
P
Faccio
Daniele
D
Di Trapani
Paolo
P
Dubietis
Audrius
A
Piskarskas
Algis
A
Couairon
Arnaud
A
Porras
Miguel
M