Presentations

    Femtosecond micromachining of waveguides in a Faraday material, at Photonics West 2006 (San Jose, CA), Tuesday, January 24, 2006
    The use of femtosecond lasers for micromachining purposes has grown significantly over the past decade. Femtosecond micromachining of photonic devices has been demonstrated using only a few nanojoules of energy from a laser oscillator. This oscillator-only technique has recently become increasingly valuable as a micromachining tool.

    Faraday isolators have not yet been realized using this ultrafast micromachining technique. A Faraday isolator is an important device because it functions as an optical diode, allowing signals to propagate only in one direction. It is particularly useful in...

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    Ultrafast reflectivity dynamics in highly excited bulk ZnO, at Photonics West 2008 (San Jose, CA), Sunday, January 20, 2008:
    Large bandgap semiconductors like ZnO are currently of interest as detectors and lasing media. Advances in these device technologies rely on a fundamental understanding of carrier dynamics and excitonic effects at high excitation densities. High carrier densities in semiconductors can be induced by excitation with intense, ultrashort laser pulses, and the resulting dynamics can be determined through our broadband time-resolved pump-probe reflectivity technique. We use a Ti:Sapph fs-laser pulse to excite the c-plane of a crystalline ZnO sample just below its damage threshold of 3 kJ/m2, under... Read more about Ultrafast reflectivity dynamics in highly excited bulk ZnO
    Ultrafast exciton dynamics in highly excited bulk ZnO, at Photonics West 2009 (San Jose, CA), Wednesday, January 28, 2009:
    Large bandgap semiconductors like ZnO are currently of interest as light emitters in the blue-UV spectral range. Advances in these technologies rely on a fundamental understanding of carrier dynamics and excitonic effects at high excitation densities. Researchers have described highly photo-excited ZnO using the polariton model. However, at high excitation, one would expect screening effects to come into play, such that the polariton model would no longer hold. With high carrier densities induced by intense, ultrashort laser pulses, we are able to monitor exciton dynamics through our micro-... Read more about Ultrafast exciton dynamics in highly excited bulk ZnO