Events

Physics education research (PER) has resulted in new materials, approaches to teaching, and theoretical understanding of student learning in physics. PER has influenced practices in introductory physics courses, impacting tens of thousands of students, and a growing number of current and future teachers. While the field has demonstrated positive effects in many instances, remarkably little work has gone into understanding how research-based, educational reforms are replicated and sustained. This talk will begin by discussing the curricular choices we have made at CU Boulder, and why.

The effective modeling of electromagnetic waves on unbounded domains by numerical techniques, such as the finite difference or the finite element method, is dependent on the particular absorbing boundary condition used to truncate the computational domain. In 1994, J. P. Berenger created the perfectly matched layer (PML) technique for the reflection-less absorption of electromagnetic waves in the time domain. The PML is an absorbing layer that is placed around the computational domain of interest in order to attenuate outgoing radiation.

At most universities, including the University of Colorado, upper-division physics courses are taught using a traditional lecture approach that does not make use of many of the instructional techniques that have been found to improve student learning at the introductory level. We are transforming an upper-division E&M course using principles of active engagement and learning theory, guided by the results of observations, interviews, and analysis of student work at CU and elsewhere.

BaCuChF (Ch = S, Se, Te) is a non-oxide wide-bandgap p-type semiconductor. This combination of properties is quite rare, but very desirable for applications in optoelectronic devices, such as CdTe and CIGS solar cells, organic bulk heterojunction solar cells and organic light-emitting diodes (OLEDs). Realization of BaCuChF in these thin film devices requires a fundamental understanding of its surface and interfacial properties. The first part of my talk will be focused on basic principles of x-ray and ultraviolet photoelectron spectroscopy techniques (XPS/UPS).

The strikingly colorful world of insects is in large part the result of optical interference produced by the interaction of light with precisely ordered, periodic bio-polymeric structures, incorporated into their exoskeletons. Such structural colors have recently gained tremendous interest for the use as photonic crystals with promising potential for energy and information technology applications.

6 October 2009

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2009 with one half to

Charles K. Kao
Standard Telecommunication Laboratories, Harlow, UK, and Chinese University of Hong Kong

"for groundbreaking achievements concerning the transmission of light in fibers for optical communication"

and the other half jointly to

Willard S. Boyle and George E. Smith
Bell Laboratories, Murray Hill, NJ, USA

"for the invention of an imaging semiconductor circuit – the CCD sensor"

The masters of light

II-VI based magnetic semiconductors (MSs) with a direct and wide optical band gap are expected to show high potential for optical applications utilizing short wavelength laser diodes (LDs), such as 532-nm green and 475-nm blue LDs. II-VI MSs Zn1-xMnxTe and Zn1-xMnxSe exhibit their absorption edges at 428-544 nm and 428-458 nm, respectively. The edge is not so influenced by the Mn concentration, as is typically observed in Cd1-xMnxTe. We have confirmed that the Faraday rotation F in the ZnMnTe films deposited on quartz glass (QG) substrates is large near the absorption edge.

Two of the principal challenges in biomedical nanoscience and personalized medicine are: a) the detection of disease at the earliest possible time prior to its ability to cause damage (diagnostics and imaging) and b) delivering treatment at the right place, at the right time whilst minimizing unnecessary exposure (targeted therapy with a triggered release). The former is dominated by optical methods, emerging “life on a chip” systems and the versatile magnetic resonance imaging technology. The latter remains an ongoing challenge.