Presentations

    Stopping time, at International Year of Light Special Lecture at the 11th Conference on Lasers and Electro- Optics Pacific Rim (CLEO-PR 2015) (Busan, South Korea), Monday, August 24, 2015:
    Time is of philosophical interest as well as the subject of mathematical and scientific research. Even though it is a concept familiar to most, the passage of time remains one of the greatest enigmas of the universe. The philosopher Augustine once said: "What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks me, I do not know." The concept time indeed cannot be explained in simple terms. Emotions, life, and death - all are related to our interpretation of the irreversible flow of time. After a discussion of the concept of time, we will review... Read more about Stopping time
    Teaching and Research: Inseparable responsibilities of the modern physicist, at Advisory Committee Meeting, National Science Foundation, Directorate for Mathematical and Physical Sciences (Arlington, VA), Thursday, April 13, 2000:
    Mention the word ""physics"" to the average high-school student and you are not likely to see many happy faces. Public opinion of science in general--and physics in particular--is not high. More importantly, misunderstandings about the goals and procedures of physics are rampant. In part, these problems arise because physics education has focused nearly exclusively on generating a steady supply of future physicists. The need to educate non-majors, let alone the public at large, has generally not been perceived as an important mission of physics departments. Now that the need for physics is no... Read more about Teaching and Research: Inseparable responsibilities of the modern physicist
    Teaching and Research: Inseparable responsibilities of the modern physicist, at APS Centennial Meeting 1999 (Atlanta, GA), Tuesday, March 23, 1999:
    Mention the word ""physics"" to the average high-school student and you are not likely to see many happy faces. Public opinion of science in general--and physics in particular--is not high. More importantly, misunderstandings about the goals and procedures of physics are rampant. In part, these problems arise because physics education has focused nearly exclusively on generating a steady supply of future physicists. The need to educate non-majors, let alone the public at large, has generally not been perceived as an important mission of physics departments. Now that the need for physics is no... Read more about Teaching and Research: Inseparable responsibilities of the modern physicist
    Teaching Physics, Conservation Laws First, at Siam Physics Congress 2015 (Krabi, Thailand), Thursday, May 21, 2015:
    The Principles and Practice of Physics is a groundbreaking new calculus-based introductory physics textbook that uses a unique organization and pedagogy to allow students to develop a true conceptual understanding of physics alongside the quantitative skills needed in the course. The book organizes introductory physics around the conservation principles and provides a unified contemporary view of introductory physics. In this talk we will discuss the unique architecture of the book, the conservation-laws-first approach, and results obtained with this book.
    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
    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
    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.
    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
    Laser induced microexplosions and applications in laser micromachining, at Annual Meeting of the Stanford Photonics Research Center, Standord University (Palo Alto, CA), Saturday, September 15, 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 Laser induced microexplosions and applications in laser micromachining
    Femtosecond laser micromachining of transparent materials for photonics and biology, at International Symposium on Photonic Glasses 2002 (Shanghai, China), Tuesday, October 15, 2002:
    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 Femtosecond laser micromachining of transparent materials for photonics and biology

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