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2008

Peer Instruction, at Surrey Centre for Excellence in Professional Training and Education Lecture, University of Surrey (Guildford, United Kingdom), Friday, March 7, 2008:
talk_1373.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
Memorization or understanding: are we teaching the right thing?, at Surrey Centre for Excellence in Professional Training and Education Lecture, University of Surrey (Guildford, United Kingdom), Friday, March 7, 2008:
talk_1326.pdf
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?
Nonlinear optics at the nanoscale, at Physics Colloquium, University of Massachusetts Lowell (Lowell, MA), Wednesday, February 13, 2008:
talk_1370.pdf
We explore nonlinear optical phenomena at the nanoscale by launching femtosecond laser pulses into long silica nanowires. Using evanescent coupling between wires we demonstrate a number of nanophotonic devices. At high intensity the nanowires produce a strong supercontinuum over short interaction lengths (less than 20 mm) and at a very low energy threshold (about 1 nJ), making them ideal sources of coherent white-light for nanophotonic applications. The spectral broadening reveals an optimal fiber diameter to enhance nonlinear effects with minimal dispersion. We also present a device that... Read more about Nonlinear optics at the nanoscale
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
Ultrafast reflectivity dynamics in highly excited bulk ZnO, at Photonics West 2008 (San Jose, CA), Sunday, January 20, 2008:
talk_1371.pdf
Large bandgap semiconductors like ZnO are currently of interest as detectors and lasing media. Advances in these device technologies rely on a fundamental understanding of carrier dynamics and excitonic effects at high excitation densities. High carrier densities in semiconductors can be induced by excitation with intense, ultrashort laser pulses, and the resulting dynamics can be determined through our broadband time-resolved pump-probe reflectivity technique. We use a Ti:Sapph fs-laser pulse to excite the c-plane of a crystalline ZnO sample just below its damage threshold of 3 kJ/m2, under... Read more about Ultrafast reflectivity dynamics in highly excited bulk ZnO
How the mind tricks us: visualizations and visual illusions, at the Centre for the Study of Learning and Performance and the Centre for Teaching and Learning Services, Concordia University (Montreal, Canada), Thursday, January 17, 2008:
talk_1366.pdf
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
Confessions of a converted lecturer, at the Centre for the Study of Learning and Performance and the Centre for Teaching and Learning Services, Concordia University (Montreal, Canada), Thursday, January 17, 2008:
talk_1364.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
Wrapping light around a hair, at Physics Colloquium, McGill University (Montreal, Canada), Thursday, January 17, 2008:
talk_1367.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
Confessions of a converted lecturer, at T-PULSE/TLS Education Talk, McGill University (Montreal, Canada), Wednesday, January 16, 2008:
talk_1362.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

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