Patrice L. Baldeck

Learn More
Nanoscale features as small as 65 ± 5 nm have been formed reproducibly by using 520 nm femtosecond pulsed excitation of a 4,4'-bis(din -butylamino)biphenyl chromophore to initiate crosslinking in a triacrylate blend. Dosimetry studies of the photoinduced polymerization were performed on chromophores with sizable two-photon absorption cross-sections at 520(More)
Archimedes micro-screws have been fabricated by three-dimensional two-photon polymerization using a Nd:YAG Q-switched microchip laser at 532nm. Due to their small sizes they can be easily manipulated, and made to rotate using low power optical tweezers. Rotation rates up to 40 Hz are obtained with a laser power of 200 mW, i.e. 0.2 Hz/mW. A photo-driven(More)
Cross-phase modulation (XPM) and induced focusing occur when copropagating ultrafast pulses interact in a nonlinear medium. XPM and induced focusing are investigated as new techniques to control the spectral, temporal, and spatial properties of ultrafast pulses with femtosecond time response. In this paper we review our most recent measurements on (1)(More)
This study proposes an optically driven complex micromachine with an Archimedes microscrew as the mechanical power, a sphere as a coupler, and three knives as the mechanical tools. The micromachine is fabricated by two-photon polymerization and is portably driven by optical tweezers. Because the microscrew can be optically trapped and rotates spontaneously,(More)
In this study, we characterized the rotational efficiency of the photo-driven Archimedes screw. The micron-sized Archimedes screws were fabricated using the two-photon polymerization technique. Free-floating screws trapped by optical tweezers align in the laser irradiation direction and rotate spontaneously. The influences of the screw pitch and the number(More)
Two europium complexes with bis(bipyridine) azamacrocyclic ligands featuring pendant arms with or without π-conjugated donor groups are synthesized and fully characterized by theoretical calculations and NMR spectroscopy. Their photophysical properties, including two-photon absorption, are investigated in water and in various organic solvents. The(More)
We study experimentally the nonlinear dynamics of two-color optical vortex beams in the presence of second-harmonic generation combined with the effects of photo-and thermal refraction, as well as self-and induced-phase modulation. We use an iron-doped lithium niobate crystal as a nonlinear medium for the vortex propagation and observe experimentally,(More)
  • 1