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Wrapping light around a hair, at NCLT Faculty Workshop on Nanoscale Science & Engineering Education, Alabama A&M University (Huntsville, AL), Thursday, March 27, 2008:
talk_1325.pdf
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
High photoconductive gain and broad spectral sensitivity enabled by femtosecond laser doping of silicon, at SPIE Photonics West 2008 (San Jose, CA), Wednesday, January 23, 2008:
talk_1337.pdf
Femtosecond laser doping of silicon produces near-unity absorption from the ultraviolet to the short wave infrared. The resulting ‘black silicon’ has great potential for applications in photoactive devices. We have successfully incorporated black silicon into new silicon devices with unique characteristics including: high efficiency, room-temperature photoconductive gain, broad-spectral silicon photodetection, and enhanced near-infrared photovoltaic response. We present the current state of the research and discuss the potential for this processing technique to develop other new materials.
Femtosecond laser-nanostructured substrates for single molecule surface-enhanced Raman spectroscopy, at Photonics West (San Jose, California), Tuesday, January 22, 2008:
talk_1368.pdf
We present a new type of surface-enhanced Raman scattering (SERS) substrate that exhibits extremely large and uniform cross-section enhancements over a macroscopic (>25mm2) area. The substrates are fabricated using an extremely simple procedure: a train of femtosecond laser pulses is used to structure a silicon wafer with an array of submicron-sized spikes, and a silver film is subsequently deposited on the structured surface. SERS signals from adsorbed molecular dyes indicate a spatially uniform enhancement factor (ca. 10^7) that is consistently observed over a wide range of excitation... Read more about Femtosecond laser-nanostructured substrates for single molecule surface-enhanced Raman spectroscopy
Peer Instruction Workshop, at AAPT New Faculty Workshop, American Center for Physics (College Park, MD), Friday, November 9, 2007:
talk_1357.pdf
The basic goals of Peer Instruction are to encourage and make use of student interaction during lectures, while focusing students' attention on underlying concepts and techniques. The method has been assessed in many studies using standardized, diagnostic tests and shown to be considerably more effective than the conventional lecture approach to teaching. Peer Instruction is now used in a wide range of science and math courses at the college and secondary level. In this workshop, participants will learn about Peer Instruction, serve as the “class” in which Peer Instruction is demonstrated,... Read more about Peer Instruction Workshop
Introduction to Peer Instruction, at AAPT New Faculty Workshop, American Center for Physics (College Park, MD), Thursday, November 8, 2007:
talk_1323.pdf
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.
Silica nanowires: manipulating light at the nanoscale, at Asia-Pacific Optical Communications 2007 (Wuhan, China), Saturday, November 3, 2007
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 20 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
Interactive Teaching: Turning a Large Lecture into a Seminar, at MIT Mechanical Engineering Teaching and Learning Retreat, Massachusetts Insitute of Technology (Cambridge, MA 02138), Sunday, September 23, 2007:
talk_1345.pdf
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
Nonlinear optics at the nanosale, at Ultrafast Optics 2007 (Santa Fe, NM), Wednesday, September 5, 2007:
talk_1319.pdf
Silica nanowires are a model system for the propagation of light at the nanoscale. Because of the tight confinement of light provided by these nanowires, nonlinear effects can be observed with pulse energies in the picojoule range, opening the door to a new class of nanophotonic devices. In addition, silica nanowires permit convenient coupling between macroscale and nanoscale. We will show how silica nanowires can be used to study waveguiding, mode propagation, and nonlinear effects in single ZnO nanowires.
Wrapping light around a hair, at Advances on Nanophotonics II, Centro Ettore Majorana (Erice, Italy), Tuesday, June 26, 2007:
talk_1336.pdf
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

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