Invited

Femtosecond Laser Micromachining: Applications in Technology and Biology, at 2005 SPIE Photonics West Conference, Symposium OE04: Ultrafast Phenomena in Semiconductors and Nanostructure Materials IX (San Jose, CA), Wednesday, January 26, 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 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
Femtosecond-laser micromachining of silicon for novel optoelectronic devices, at 2005 SPIE Photonics West Conference (San Jose, CA), Tuesday, January 25, 2005:
Silicon is the most commonly used semiconductor in micro- and optoelectronics. However, silicon is not the best material for all applications: as an indirect band-gap material, it is a poor light emitter; silicon cannot be used to detect many important communications wavelengths; and silicon solar cells fail to convert nearly a third of the suns’ spectrum into electricity. The low cost and large manufacturing infrastructure drives research to alter the properties of silicon rather than rely on more exotic semiconductor materials. We present a novel technique that uses the intense conditions... Read more about Femtosecond-laser micromachining of silicon for novel optoelectronic devices
Subwavelength-diameter silica wires for microscale optical components, at SPIE Photonics West 2005 Conference (San Jose, CA), Monday, January 24, 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
Femtosecond laser micromachining of glass for photonics applications, at Glass & Optical Materials Division Fall 2004 Meeting (Cape Canaveral, FL), Monday, November 8, 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 of glass for photonics applications
Peer Instruction: Discussion and brains-on demonstration, at 2004 New Faculty Workshop, American Center for Physics (College Park, MD), Friday, November 5, 2004:
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: Discussion and brains-on demonstration
Active learning and interactive lectures, at 2004 New Faculty Workshop, American Center for Physics (College Park, MD), Friday, November 5, 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. I will show how shifting the focus in lectures from delivering information to synthesizing... Read more about Active learning and interactive lectures
Femtosecond laser-assisted microstructuring of silicon surfaces for novel detector, sensing, and display technologies, at 41st Annual Technical Meeting of the Society of Engineering Science, University of Nebraska, Lincoln (Lincoln, NE), Monday, October 11, 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.
Wrapping light around a hair, at InternationalConference on Applications of Lasers and Electro-Optics 2004 (San Francisco, CA), Monday, October 4, 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 IInd Mexican Meeting on Mathematical and Experimental Physics, Colegio Nacional (Mexico City, Mexico), Friday, September 10, 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, round 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

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