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2007

Two-photon microfabrication of structures containing, at 2007 MRS Fall Meeting (Boston, MA, USA), Thursday, November 29, 2007:
talk_1346.pdf
We present the two-photon microfabrication of structures containing the bio-polymer Chitosan, using a guest/host scheme. The host resin we used consists of tris(2-hydroxyethyl)isocyanurate triacrylate and ethoxylated(6) trimethyl-lolpropane triacrylate. As guest material we used the Chitosan, which is a linear cationic polysaccharide obtained by deacetylation of chitin, a structural polysaccharide normally encountered in crustaceans. There are several potential applications for chitosan, mainly due to its biodegradability and biocompatibility. We induced the two-photon absorption... Read more about Two-photon microfabrication of structures containing
Black silicon: From accidental discovery to company, at the Society for Creativity and Innovation, Harvard University (Cambridge, MA), Monday, November 19, 2007:
talk_1358.pdf
Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The resulting textured surface is highly absorbing and looks black to the eye. The properties of this 'black silicon' make it useful for a wide range of commercial devices. In particular, we have been able to fabricate highly-sensitive PIN photodetectors using this material. The sensitivity extends to wavelengths of 1600 nm making them particularly useful for applications in communications and remote sensing.
Subcellular surgery and nanosurgery, at Baetjer Colloquium, Princeton University (Princeton, NJ), Friday, November 16, 2007:
talk_1340.pdf
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
Wrapping light around a hair, at Baetjer Colloquium, Princeton University (Princeton, NJ), Thursday, November 15, 2007:
talk_1339.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
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
Wrapping light around a hair, at Nanotech 2007: A Symposium for Teachers, Museum of Science (Boston, MA), Friday, October 26, 2007:
talk_1321.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
Subcellular surgery and nanosurgery, at Physics Colloquium, University of Kentucky (Lexington, KY), Thursday, October 25, 2007:
talk_1355.pdf
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
Wrapping light around a hair, at SPS/DSP Lunch Talk, University of Kentucky (Lexington, KY), Thursday, October 25, 2007:
talk_1356.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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