University of Minnesota
School of Physics & Astronomy

Condensed Matter Seminar

Thursday, February 28th 2008
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Dr. V. Sih, Stanford University
Subject: Manipulating spins and photons in semiconductors

Understanding the interactions of electron spins and photons in semiconductors may enable the development of new devices with enhanced functionality and performance, such as spin-based devices that combine logic and storage and fast optical switches for information processing. In the first half of this talk, we describe time- and spatially-resolved optical measurements of electron spin polarization in semiconductor heterostructures. We investigate the effects of strain and quantum confinement on electron spins in semiconductors and explore methods of electrically generating spin polarization in non-magnetic materials through spin-orbit coupling and the spin Hall effect. In the second half of this talk, we focus on recent developments in photonics for applications such as on-chip light sources and optical devices. The high index contrast of silicon waveguides offers small optical modal areas so that high optical power densities can be achieved for observing nonlinear effects in compact devices, and silicon photonic devices, such as Raman lasers, amplifiers, modulators and wavelength converters, have recently been demonstrated. Finally, we discuss planar photonic crystal cavities for realizing strong localization of light with small mode volumes for achieving substantial reductions in lasing threshold.

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