Presentations

    Memorization or Understanding: Are we teaching the right thing?, at Physics Colloquium, University of Colorado (Boulder, CO), Wednesday, August 28, 2002:
    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. Students get frustrated because they are unable to grasp simple concepts. Instructors get... Read more about Memorization or Understanding: Are we teaching the right thing?
    Femtosecond Laser Micromachining: Applications in Technology and Biology, at Physics Colloquium, UMass Lowell (Lowell, MA), Wednesday, October 30, 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: Applications in Technology and Biology
    Memorization or understanding: Are we teaching the right thing?, at Physics Colloquium, UCLA (Los Angeles, CA), Thursday, March 13, 2003:
    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. Students get frustrated because they are unable to grasp simple concepts. Instructors get... Read more about Memorization or understanding: Are we teaching the right thing?
    Memorization or understanding: Are we teaching the right thing?, at Physics Colloquium, SUNY Buffalo (Buffalo, NY), Thursday, April 17, 2003:
    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. Students get frustrated because they are unable to grasp simple concepts. Instructors get... Read more about Memorization or understanding: Are we teaching the right thing?
    Peer Instruction: Methods and Techniques, at Physics Colloquium, Ohio University (Athens, OH), Friday, June 6, 2003:
    There is a crisis confronting undergraduate Physics education today. Studies indicate that most large undergraduate classes fail to convey the concepts or the context of Physics to the students. It has been suggested the lack of interaction in the classes is fundamentally to blame for this problem. We offer a way of redesigning the classroom so interaction is introduced at every level. This pedagogocal method, called Peer Instruction has been shown to be effective when used by different instructors in many different environments. We also describe some technological tools that we have... Read more about Peer Instruction: Methods and Techniques
    The Interactive Learning Toolkit, at Physics Colloquium, Worcester Polytechnic Institute (WPI) (Worchester, MA), Monday, September 8, 2003:
    Research into new approaches to undergraduate science education has led to significant changes in our understanding of how large classes should be taught. Instructors who have implemented these new research based techniques have experienced dramatic improvements in student understanding. We have taken two proven pedagogical methods, 'Just in Time Teaching' (JiTT) and 'Peer Instruction' (PI) and implemented them in our 'Interactive Learning Toolkit' (ILT). In developing ILT, our focus has been to save the instructor time and use technology to bring interaction in the classroom.
    Interactive Learning Toolkit: Tools for the Interactive Classroom, at Invited Talk, University of Limerick (Co. Limerick, Ireland), Wednesday, December 17, 2003:
    Research-based interactive learning techniques have dramatically improved student understanding. We have created the 'Interactive Learning Toolkit' (ILT), a web-based learning management system, to help implement two such pedagogies: Just in Time Teaching and Peer Instruction. Our main goal in developing this toolkit is to save the instructor time and effort and to use technology to facilitate the interaction between the students and the instructor (and between themselves). After a brief review of both pedagogies, I will demonstrate the many new exciting features of the ILT. I will show how... Read more about Interactive Learning Toolkit: Tools for the Interactive Classroom
    Manipulating matter with light, at Physics Colloquium, University of Missouri-Columbia (Columbia, MO), Thursday, February 26, 2004:
    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 Manipulating matter with light
    Black silicon: changing structure and properties with light, at Physics Colloquium, Haverford College (Haverford, PA), Monday, March 1, 2004:
    Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer changes its structure and properties dramatically: the formerly smooth, highly reflective surface becomes covered with a forest of sharp microspikes. This microstructured surface is highly absorbing even at wavelengths to which the original wafer is transparent. This talk will describe the properties of this microstructured surface and discuss why the microspikes form and what is responsible for the change in optical properties.
    Femtosecond laser-assisted microstructuring of silicon surfaces for novel detector, sensing, and display technologies, at Physics Colloquium, University of Massachusetts Lowell (Lowell, MA), Wednesday, March 10, 2004:
    Irridiating silicon surfaces with trains of ultrashort laser pulses in the presence of a sulfur containing gas drastically changes the structure and properties of silicon. The normally smooth and highly reflective surface develops a forest of sharp microscopic spikes. The microstructured surface is highly absorbing even at wavelengths beyond the bandgap of silicon and has many interesting novel applications.
    Memorization or understanding: Are we teaching the right thing?, at Physics and Astronomy Colloquium, Michigan State University (East Lansing, MI), Thursday, March 18, 2004:
    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. Students get frustrated because they are unable to grasp simple concepts. Instructors get... Read more about Memorization or understanding: Are we teaching the right thing?
    Femtosecond Laser Micromachining: Applications in Technology and Biology, at Joint University of Pittsburgh and Carnegie Mellon University Colloquium, Carnegie Mellon University (Pittsburgh, PA), Monday, April 5, 2004:
    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: Applications in Technology and Biology
    Controlling coherent optical phonons in tellurium, at JILA Colloquium, University of Colorado (Boulder, CO), Tuesday, April 20, 2004:
    Using time-resolved reflectometry we measure the dielectric function of tellurium following excitation with a femtosecond laser pulse. The dielectric function reveals the ultrafast dynamics of coherent phonons in Te. Oscillations in the bonding-antibonding splitting allow for THz modulation of a semiconductor-semimetal transition. Using two-pulse sequences, we can control the phonons, stabilizing the bandstructure in the semimetallic state.
    Wrapping light around a hair, at Condensed Matter and Applied Physics Colloquium, Harvard University (Cambridge, MA), Friday, May 7, 2004:
    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 very uniform 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 possible to... Read more about Wrapping light around a hair
    Wrapping light around a hair, at Physics Colloquium, University of Massachusetts Lowell (Lowell, MA), Wednesday, September 22, 2004:
    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 very uniform 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 possible to... Read more about Wrapping light around a hair
    Wrapping light around a hair, at Physics Colloquium, University of Missouri-Rolla (Rolla, MO), Thursday, October 21, 2004:
    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 Wrapping light around a hair
    Visualizations and visual illusions: how the mind tricks us, at Center for Astrophysics Lecture, Harvard University (Cambridge, MA), Tuesday, January 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.
    Wrapping light around a hair: manipulating light at the nanoscale, at Physics Colloquium, University of Washington (Seattle, WA), Monday, October 10, 2005:
    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 Wrapping light around a hair: manipulating light at the nanoscale

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