Presentations

    Femtosecond Materials Processing I: Transparent and soft materials, at Tsing Hua Univeristy (Beijing, China), Wednesday, December 17, 2014:
    The intersection of materials research and ultrafast optical science is producing many valuable fundamental scientific results and applications, and the trend is expected to evolve as new and exciting discoveries are made. Femtosecond laser micromachining presents unique capabilities for three-dimensional, material-independent, sub-wavelength processing. At the same time the surface processing of materials permits the creation of novel materials that cannot (yet) be created under other conditions. In the first part of this talk we will discuss how when the ultashort laser pulses are focused... Read more about Femtosecond Materials Processing I: Transparent and soft materials
    Femtosecond Materials Processing II: Nontransparent materials, at Tsing Hua Univeristy (Beijing, China), Wednesday, December 17, 2014:
    The intersection of materials research and ultrafast optical science is producing many valuable fundamental scientific results and applications, and the trend is expected to evolve as new and exciting discoveries are made. Femtosecond laser micromachining presents unique capabilities for three-dimensional, material-independent, sub-wavelength processing. At the same time the surface processing of materials permits the creation of novel materials that cannot (yet) be created under other conditions. In the first part of this talk we will discuss how when the ultashort laser pulses are focused... Read more about Femtosecond Materials Processing II: Nontransparent materials
    Laser induced microexplosions in transparent materials, at CLEO/QELS '97 (Baltimore, MD), Friday, May 23, 1997
    We recently discovered that 200-nm diameter structures can be created inside transparent materials by ultrafast-laser driven microexplosions. Applications include high-density 3-D data storage, fabrication of 3-D optical elements, and novel materials processing. We present the results of optical and structural examinations and discuss the physical processes involved.
    Laser-induced microexplosions: creating stellar conditions on an optical bench, at Joint SPIE and Department of Electrical and Electrical Engineering Seminar, The University of Hong Kong (Hong Kong, Hong Kong), Saturday, October 23, 1999:
    Using femtosecond laser pulses we study the effects of intense laser radiation on transparent materials. By tightly focusing these laser pulses below the surface of transparent materials, we initiate highly nonlinear absorption processes which produce a dense, highly-excited plasma inside the sample. The high density, tightly-confined plasma leads to a micron-sized explosion within the material, with temperatures and pressures approaching stellar conditions. We have recently shown that it is possible to create internal submicron-sized structures by optically initiating microexplosions inside... Read more about Laser-induced microexplosions: creating stellar conditions on an optical bench
    Micromachining of bulk glass with tightly-focused femtosecond laser pulses, at XI International Symposium Ultrafast Phenomena in Spectroscopy, Academia Sinica (Taipei, Taiwan), Tuesday, October 26, 1999:
    By focusing femtosecond laser pulses with high numerical-aperture microscope objectives, we micromachine optical glass using energies that are in the range of modern laser oscillators. When a femtosecond laser pulse is tightly focused inside a transparent material, energy deposition occurs only at the focus, where the laser intensity is high enough to cause absorption through nonlinear processes. When enough energy is deposited, the material is damaged and a localized change in the index of refraction is produced. By scanning the focus through the sample, very precise, three-dimensional... Read more about Micromachining of bulk glass with tightly-focused femtosecond laser pulses
    Interactions of Femtosecond Laser Pulses with Transparent Materials, at Physics colloquium, University of Massachusetts at Lowell (Lowell, MA), Wednesday, April 12, 2000:
    Usually when light goes through a piece of glass, nothing happens to either the light nor the glass, i.e. the glass is transparent. With a powerfull femtosecond laser pulse, however, both the laser light and the glass can be changed. We study the interaction of intense, femtosecond laser pulses with bulk transparent materials. The intensity of a tightly-focused, femtosecond laser pulse can be high enough to cause nonlinear absorption of laser energy by the transparent material. When enough energy is deposited, permanent material change results. The absorption and therefore the material... Read more about Interactions of Femtosecond Laser Pulses with Transparent Materials
    Laser-Solid Interactions for Materials Processing, at 2000 Materials Research Science Meeting (San Francisco, CA), Wednesday, April 26, 2000:
    By focusing femtosecond laser pulses with high numerical-aperture microscope objectives, we micromachine optical glass using energies that are in the range of modern laser oscillators. When a femtosecond laser pulse is tightly focused inside a transparent material, energy deposition occurs only at the focus, where the laser intensity is high enough to cause absorption through nonlinear processes. When enough energy is deposited, a localized change in the index of refraction is produced, i.e. the material is damaged. By scanning the focus through the sample, very precise, three-dimensional... Read more about Laser-Solid Interactions for Materials Processing
    Laser induced microexplosions: Ultrafast physics with clinical applications, at Chemical Center Seminar, Lund University (Lund, Sweden), Monday, May 22, 2000:
    Recently there has been much interest in using femtosecond laser pulses in surgical applications. For example, femtosecond lasers could replace the nanosecond systems currently used for opthalmic photodisruption, providing improved surgical precision and adding versatility. In surgical applications, it is the high intensity of femtosecond laser pulses that is exploited. By tightly focusing these short pulses, the intensity becomes high enough to cause nonlinear absorption inside a transparent material (such as the vitreous humor). The absorption produces a hot plasma inside the sample that is... Read more about Laser induced microexplosions: Ultrafast physics with clinical applications
    Microexplosions: controlling matter with light, at Frontiers in Chemistry and Materials Science Symposium, Lawrence Livermore National Laboratory (Livermore, CA), Thursday, October 19, 2000:
    Light travels undisturbed through a window pane because glass is transparent -- light and glass don't interact. With a powerful femtosecond laser pulse, however, nonlinear processes give rise to light-matter interactions that open the door to new studies in materials science, chemistry, condensed matter physics, and life sciences. Even at very modest energies, the intensity of a tightly-focused, femtosecond laser pulse can be high enough to cause nonlinear absorption of laser energy by a transparent material. The absorption is confined at the focus producing extreme conditions in the... Read more about Microexplosions: controlling matter with light
    Femtosecond micromachining of transparent materials, at OSA 2000 Annual Meeting (Providence, RI), Tuesday, October 24, 2000:
    By tightly-focusing femtosecond laser pulses, we achieve the intensity required for permanent structural change in transparent materials with only nanojoules of energy. We discuss the mechanisms and morphology of bulk structural changes produced by femtosecond laser pulses, and describe recent work on the direct writing of photonics devices using only a laser oscillator.
    Laser-induced microexplosions in transparent solids and liquids, at Physics Seminar, University of Missouri-Rolla (Rolla, MI), Friday, April 13, 2001:
    Using femtosecond laser pulses we study the effects of intense laser radiation on transparent materials. By tightly focusing these laser pulses below the surface of transparent materials, we initiate highly nonlinear absorption processes which produce a dense, highly-excited plasma inside the sample. The high density, tightly-confined plasma leads to a micron-sized explosion within the material, with temperatures and pressures approaching stellar conditions. We have recently shown that it is possible to create internal submicron-sized structures by optically initiating microexplosions inside... Read more about Laser-induced microexplosions in transparent solids and liquids
    Micromachining and laser processing with ultrashort laser pulses, at Second International Symposium on Laser Precision Microfabrication (LPM2001) (Singapore), Wednesday, May 16, 2001:
    When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells. In this talk we will review recent results obtained in... Read more about Micromachining and laser processing with ultrashort laser pulses

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