HOME / PRESENTATIONS /

2008

Ultrafast and ultrasmall: femtosecond pulses and nanophotonics, at 2008 ITRI Femtosecond Laser International Forum, ITRI South (Kaohsiung, Taiwan), Tuesday, October 14, 2008:
talk_1414.pdf
Femtosecond laser pulses provide an opportunity to fabricate optical devices at the microscale and to design new materials for optoelectronic applications. By marrying the ultrafast with the ultrasmall we can fabricate novel nonlinear nanophotonic devices that can serve as all-optical logic gates for future telecommunication needs. In this lecture I will provide an overview of our work on femtosecond laser micromachining of transparent materials, femtosecond laser doping of semiconductors, and recent advances we have made to realize nanowire based all-optical logic gates.
Science and engineering education, at 2008 Science and Technology in Society Forum (Kyoto, Japan), Sunday, October 5, 2008:
talk_1415.pdf
Making science-based studies more attractive to students is a worldwide issue. This session will cover science and engineering education at all levels, from K-12 to college/university and at the application level. Businesses are feeling a shortage of the skills that ensure innovation. how can we entice a larger number of students to embark in a career in science and research? What can be done on the policy side? What is the role of the media?
Nonlinear optics at the nanoscale: all-optical logic gates, at Julius Springer Forum on Applied Physics, Harvard University (Cambridge, MA), Saturday, September 27, 2008:
talk_1412.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: all-optical logic gates
Wrapping light around a hair, at Physics Seminar, University of Iowa (Iowa City, IA), Tuesday, September 9, 2008:
talk_1407.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
How the mind tricks us: visualizations and visual illusions, at Public Lecture, University of Iowa (Iowa City, IA), Tuesday, September 9, 2008:
talk_1406.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
The scientific approach to teaching: Research as a basis for course design, at Physics Colloquium, University of Iowa (Iowa City, IA), Monday, September 8, 2008:
talk_1405.pdf
Discussions of teaching -- even some publications -- abound with anecdotal evidence. Our intuition often supplants a systematic, scientific approach to finding out what works and what doesn't work. Yet, research is increasingly demonstrating that our gut feelings about teaching are often wrong. In this talk I will discuss some research my group has done on gender issues in science courses and on the effectiveness of classroom demonstrations.
Memorization or understanding: are we teaching the right thing?, at Campus presentation, University of Iowa (Iowa City, IA), Monday, September 8, 2008:
talk_1403.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?
Peer Instruction, at University of Iowa (Iowa City, IA), Monday, September 8, 2008:
talk_1404.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
Gender and student achievement with Peer Instruction, at Physics Education Research Conference, AAPT Summer Meeting, University of Alberta (Edmonton, Alberta, Canada), Thursday, July 24, 2008:
talk_1408.pdf
We investigated the effect of physics education research-based teaching methods on the gender gap in conceptual understanding in introductory physics. We analyzed data from the introductory calculus-based mechanics course for non-majors at Harvard University taught traditionally and taught with different degrees of interactive engagement. On average, female students have lower Force Concept Inventory (FCI) pretest scores than males. Teaching with Peer Instruction not only yields significantly greater FCI posttest scores for both males and females but also reduces the FCI posttest gender gap.... Read more about Gender and student achievement with Peer Instruction
The make-believe world of real-world physics, at AAPT 2008 Summer Meeting (Millikan Award lecture), University of Alberta (Edmonton, AB, Canada), Tuesday, July 22, 2008:
talk_1396.pdf
That physics describes the real world is a given for physicists. In spite of tireless efforts by instructors to connect physics to the real world, students walk away from physics courses believing physicists live in a world of their own. Are students clueless about the real world? Or are we perhaps deluding ourselves and misleading our students about the real world?

Pages