Presentations

    Femtosecond Micromachining of Transparent Materials, at International School of Atomic and Molecular Spectroscopy (Erice, Sicily), Friday, May 23, 2003:
    We present an overview of femtosecond microstructuring of transparent materials. Bulk structuring of transparent materials can be achieved by focusing high-intensity femtosecond pulses. The morphology of the structures depends on the incident energy per pulse and on the focusing conditions. At high focusing conditions the damage threshold in silicate glasses is just a few nanojoules. This energy range is available from an oscillator. We have demonstrated laser writing of embedded waveguides in silicate glasses with a femtosecond oscillator. Laser machining at high laser repetition rate... Read more about Femtosecond Micromachining of Transparent Materials
    Sub-cellular nanosurgery in live cells using ultrashort laser pulses, at Photonics West (San Jose, CA), Friday, January 21, 2005:
    We use femtosecond laser pulses to selectively disrupt the cytoskeleton of a living cell and probe its mechanical properties. The nanosurgery setup is based on a home-built two-photon microscope. To image, we use a 80-MHz, 100-pJ/pulse laser beam, which is scanned across the sample; to cut, we introduce a second, 250-kHz, 1 to 5-nJ/pulse, laser beam and locally ablate sub-cellular structures. Simultaneous cutting and imaging allows us to study immediate cellular response with several hundred-nanometer spatial and less than 500-ms time resolution. We severed single actin bundles inside live... Read more about Sub-cellular nanosurgery in live cells using ultrashort laser pulses
    Sub-cellular femtosecond laser ablation, at 2005 SPIE Photonics West Conference (San Jose, CA), Wednesday, January 26, 2005:
    We study the selective ablation by femtosecond laser pulses of sub-cellular structures in bovine endothelial cells, with selectively stained microtubules, actin fibers, and nuclei. The cells are placed in a custom-built inverted fluorescence microscope with a 1.4 NA oil-immersion objective. The laser used for ablation is centered at 800 nm delivering 100-fs laser pulses at a repetition rate of 1 kHz and the typical energy delivered at the sample is 1–5nJ. To determine the structural change and the size of the laser-affected area, we use transmission electron microscopy (TEM), in addition to... Read more about Sub-cellular femtosecond laser ablation
    Sub-cellular nanosurgery in live cells using ultrashort laser pulses, at Photonics West 2006 (San Jose, CA), Sunday, January 22, 2006:
    We use femtosecond laser pulses to selectively disrupt the cytoskeleton of a living cell and probe its mechanical properties. The nanosurgery setup is based on a home-built two-photon microscope. To image, we use a 80-MHz, 100-pJ/pulse laser beam, which is scanned across the sample; to cut, we introduce a second, 250-kHz, 1 to 5-nJ/pulse, laser beam and locally ablate sub-cellular structures. Simultaneous cutting and imaging allows us to study immediate cellular response with several hundred-nanometer spatial and less than 500-ms time resolution.

    We severed single actin bundles inside...

    Read more about Sub-cellular nanosurgery in live cells using ultrashort laser pulses
    Probing cell mechanics with femtosecond laser pulses, at Photonics West 2007 (San Jose, CA), Sunday, January 21, 2007:
    We use femtosecond laser pulses to selectively disrupt the cytoskeleton of a living cell and probe its mechanical properties. Our nanosurgery setup is based on a home-built fluorescence microscope with an integrated femtosecond laser. We severed single actin bundles inside live cells to probe the local dynamics of the cytoskeleton and correlate it to global changes in cell shape. Simultaneous cutting and imaging allows us to study immediate cellular response with several hundred-nanometer spatial and less than 500-ms time resolution. The targeted actin bundle retracts rapidly after laser... Read more about Probing cell mechanics with femtosecond laser pulses