Terrance L. Worchesky

Associate Professor

Ph.D. Georgetown University

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The research in electro-optics addresses creating efficient electro-optic effects in quantum-well semiconductor structures. These structures are fabricated with molecular beam epitaxy, producing semiconductors with layers of alternating materials whose thicknesses are less than 10.0 nm. These thin layers allow the creation of structures that demonstrate quantum-well effects on a macroscopic scale. Discrete quantum-well states are created and the quantum confinement of the electrons and holes in these semiconductor results in electron-hole pairs (called excitons) which have very long room-temperature lifetimes. These long-lived excitons create strong near-infrared absorption in the material at the quantum-well energy levels. The optical absorption lines can be Stark-shifted by low bias voltages and electro-optic effects that can be easily controlled are created. These electrically and optically efficient effects are used to produce various optical devices.

Our work in optical modelling of electro-optic devices is based on an extension of the Fraunhofer-diffraction theory to multi-layered structures. The optical model created, called a beam propagator, allows the examination of the electro-magnetic field properties as a light beam moves through a layered media. At each step in the propagation the optical properties of the material can be varied and the interaction of the light wave with these materials can be taken into account. The inclusion of the electro-optic effects caused by quantum-well layers in these structures produces models that can be used to design and develop new electro-optic devices.