Presentations

    Memorization or understanding: Are we teaching the right thing?, at 229th American Chemical Society National Meeting (San Diego, CA), Sunday, March 13, 2005:
    Education is more than just transfer of information, yet that is what is mostly done in large introductory courses -- instructors present material (even though this material might be readily available in printed form) and for students the main purpose of lectures is to take down as many notes as they can. Few students have the ability, motivation, and discipline to synthesize all the information delivered to them. Yet synthesis is perhaps the most important -- and most elusive -- aspect of education. I will show how shifting the focus in lectures from delivering information to synthesizing... Read more about Memorization or understanding: Are we teaching the right thing?
    Subwavelength-diameter silica wires for microscale optical components, at SPIE Europe International Symposium: Microtechnologies for the New Millennium (Sevilla, Spain), Tuesday, May 10, 2005:
    Optical components built from structures that are tens of micrometers wide are playing a key role in current optical communication networks, optical sensors, and medical optical devices. The demand for improved performance, broader applications, and higher integration density, together with rapid advances in nanotechnology for electronics and optoelectronics, has spurred an effort to reduce the size of basic optical components. However, the miniaturization of optical components with subwavelength and nanometer-sized optical guiding structures through established fabrication methods is... Read more about Subwavelength-diameter silica wires for microscale optical components
    Visualizations and visual illusions: how the mind tricks us, at NATO ASI Course on New developments in optics and related fields: modern techniques, materials, and applications, Centro Ettore Majorana (Erice, Italy), Saturday, June 11, 2005:
    Neurobiology and cognitive psychology have made great progress in understanding how the mind processes information – in particular visual information. The knowledge we can gain from these fields has important implications for the presentation of visual information and student learning.
    Femtosecond laser micromachining: Applications in Technology and Biology, at The 8th International Conference on Laser Ablation (Banff, Canada), Monday, September 12, 2005:
    When femtosecond laser pulses are tightly focused into a transparent material, the intensity in the focal volume is high enough to cause absorption through nonlinear processes. The absorption of the laser energy excites a submicrometer-sized region of plasma inside the material, and the energy is subsequently transferred to the atoms in the form of heat and shock waves. This process permanently alters solids and ablates cellular structures in biological media [1]. Applications include high-density data storage in three dimensions, writing of waveguides and waveguide splitters in bulk glass,... Read more about Femtosecond laser micromachining: Applications in Technology and Biology
    Fundamentals and Applications of Femtosecond Laser Micromachining of Glass, at First Conference on Advances in Optical Materials (Tucson, AZ), Wednesday, October 12, 2005:
    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 of all-optical sensors.
    Materials Processing Using Ultrashort Laser Pulses, at OSA Frontiers in Optics Meeting (Tucson, AZ), Wednesday, October 19, 2005:
    Ultrashort laser pulses are an important new tool in materials processing. We will discuss the physics of short-pulse laser interactions with materials and applications in micromachining and biotechnology.
    Nonlinear optics at the nanoscale, at OSA Frontiers in Optics Meeting (Tucson, AZ), Wednesday, October 19, 2005:
    Silica nanowires allow the guiding and manipulation of light at the nanoscale. The linear optical properties of these wires can be easily modeled because they are a step-index, all-core cylindrical waveguides. The nonlinear optical properties wires open the door to novel applications in nanoscale photonics.
    Active lectures and interactive teaching, at AAPT New Faculty Workshop (College Park, MD), Friday, November 11, 2005:
    I thought I was a good teacher until I discovered my students were just memorizing information rather than learning to understand the material. Who was to blame? The students? The material? I will explain how I came to the agonizing conclusion that the culprit was neither of these. It was my teaching that caused students to fail! I will show how I have adjusted my approach to teaching and how it has improved my students' performance significantly.
    Active lectures and interactive teaching, at AAPT New Faculty Workshop, American Center for Physics (College Park, MD), Saturday, November 12, 2005:
    I thought I was a good teacher until I discovered my students were just memorizing information rather than learning to understand the material. Who was to blame? The students? The material? I will explain how I came to the agonizing conclusion that the culprit was neither of these. It was my teaching that caused students to fail! I will show how I have adjusted my approach to teaching and how it has improved my students' performance significantly.
    Subcellular surgery and nanoneurosurgery, at 36th Winter Colloquium on The Physics of Quantum Electronics (Snowbird, UT), Wednesday, January 4, 2006:
    We use femtosecond laser pulses to manipulate sub-cellular structures inside live and fixed cells. Using only a few nanojoules of laser pulse energy, we are able to selectively disrupt individual mitochondria in live bovine capillary epithelial cells, and cleave single actin fibers in the cell cytoskeleton network of fixed human fibro-blast cells. We have also used the technique to micromanipulate the neural network of C. Elegans, a small nematode. Our laser scalpel can snip individual axons without causing any damage to surrounding tissue, allowing us to study the function of individual... Read more about Subcellular surgery and nanoneurosurgery
    Femtosecond laser micromachining, at Photonics West 2006 (San Jose, CA), Tuesday, January 24, 2006:
    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.
    Silica nanowires: manipulating light at the nanoscale, at Photonics West 2006 (San Jose, CA), Thursday, January 26, 2006:
    Can light be guided by a fiber whose diameter is much smaller than the wavelength of the light? Can we mold the flow of light on the micrometer scale so it wraps, say, around a hair? Until recently the answer to these questions was ‘no’. We developed a technique for drawing long, free-standing silica wires with diameters down to 50 nm that have a surface smoothness at the atomic level and a high uniformity of diameter. Light can be launched into these silica nanowires by optical evanescent coupling and the wires allow low-loss single-mode operation. They can be bent sharply, making it... Read more about Silica nanowires: manipulating light at the nanoscale
    Subcellular surgery and nanosurgery, at CIMIT/Lester Wolfe Workshop on Femtosecond Microscopy & Microsurgery, Wellman Center for Photomedicine (Boston, MA), Tuesday, April 18, 2006:
    We use femtosecond laser pulses to manipulate sub-cellular structures inside live and fixed cells. Using only a few nanojoules of laser pulse energy, we are able to selectively disrupt individual mitochondria in live bovine capillary epithelial cells, and cleave single actin fibers in the cell cytoskeleton network of fixed human fibro-blast cells. We have also used the technique to micromanipulate the neural network of C. Elegans, a small nematode. Our laser scalpel can snip individual axons without causing any damage to surrounding tissue, allowing us to study the function of individual... Read more about Subcellular surgery and nanosurgery
    Interactive Teaching: Turning a Large Lecture into a Seminar, at Symposium on Technology in Undergraduate Education, Harvard University (Cambridge, MA 02138), Friday, June 16, 2006:
    Education is more than just transfer of information, yet that is mostly what happens in large introductory courses -- instructors present material and students take down as many notes as they can. This format tends to reinforce the idea that learning is about acquiring information rather than gaining new ways of thinking. In undergraduate science, however, learning consists primarily of developing new thinking skills; this mismatch between instruction and learning leads to students misunderstanding what science is, as well as frustration for both students and instructors. The problem has a... Read more about Interactive Teaching: Turning a Large Lecture into a Seminar
    The scientific approach to teaching: Research as a basis for course design, at 2006 Cottrell Scholars Meeting (Tucson, AZ), Saturday, July 8, 2006:
    Discussions of teaching -- even some publications -- abound with anecdotal evidence. Our intuition often supplants a systematic, scientific approach to finding out what works and what doesn't work. Yet, research is increasingly demonstrating that our gut feelings about teaching are often wrong. In this talk I will discuss some research my group has done on gender issues in science courses and on the effectiveness of classroom demonstrations.
    Active learning and interactive lectures, at AAPT New Faculty Workshop, American Center for Physics (College Park, MD), Friday, October 27, 2006:
    I thought I was a good teacher until I discovered my students were just memorizing information rather than learning to understand the material. Who was to blame? The students? The material? I will explain how I came to the agonizing conclusion that the culprit was neither of these. It was my teaching that caused students to fail! I will show how I have adjusted my approach to teaching and how it has improved my students' performance significantly.
    Femtosecond laser micromachining, at 1st International Workshop on Multiphoton Processes in Glass and Glassy Materials, University of Sydney (Sydney, Australia), Monday, December 11, 2006:
    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.
    Using short bursts of photons to manipulate biological matter at the nanoscale, at Winter Colloquium on the Physics of Quantum Electronics (Snowbird, UT), Friday, January 5, 2007:
    We use femtosecond laser pulses to manipulate sub-cellular structures inside live and fixed cells. Using only a few nanojoules of laser pulse energy, we are able to selectively disrupt individual mitochondria in live bovine capillary epithelial cells, and cleave single actin fibers in the cell cytoskeleton network of fixed human fibro-blast cells. We have also used the technique to micromanipulate the neural network of C. Elegans, a small nematode. Our laser scalpel can snip individual axons without causing any damage to surrounding tissue, allowing us to study the function of individual... Read more about Using short bursts of photons to manipulate biological matter at the nanoscale
    Femtosecond laser micromachining, at MIT Center for Integrated Photonic Systems Annual Meeting, MIT (Cambridge, MA, USA), Thursday, May 3, 2007:
    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.

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