Two-photon polymerization with variable repetition rate bursts of femtosecond laser pulses.

We describe fabrication of microstructures by two-photon polymerization using bursts of femtosecond laser pulses. With the aid of an acousto-optic modulator driven by a function generator, two-photon polymerization is performed at variable burst repetition rates. We investigate how the time between the bursts of laser pulses influences the ultimate dimensions of lines written in a photosensitive resin.

In situ and real time monitoring of two-photon polymerization using broadband coherent anti-Stokes Raman scattering microscopy.

We demonstrate in situ and real time characterization of two-photon polymerization (TPP) by means of broadband coherent anti-Stokes Raman scattering (CARS) microscopy. The same experimental setup based on one femtosecond oscillator is used to perform both TPP and broadband CARS microscopy. We performed in situ imaging with chemical specificity of three-dimensional microstructures fabricated by TPP, and successfully followed the writing process in real time.

Characterization of microstructures fabricated by two-photon polymerization using coherent anti-stokes Raman scattering microscopy.

We demonstrate the possibility to image microstructures fabricated by two-photon polymerization (TPP) using coherent anti-Stokes Raman scattering (CARS) microscopy. The imaging contrast based on chemical selectivity attained by CARS microscopy is used to gather qualitative information on TPP. Upon the basis of detailed knowledge of the characteristic signatures of the photoresist Raman spectrum, quantitative relationships between laser writing conditions and polymer cross-linking are demonstrated.