Abstract-Below gap optical absorption in GaAs driven by intense, single-cycle coherent transition radiation

J. Goodfellow, M. Fuchs, D. Daranciang, S. Ghimire, F. Chen, H. Loos, D. A. Reis, A. S. Fisher, and A. M. Lindenberg  »View Author Affiliations

Optics Express, Vol. 22, Issue 14, pp. 17423-17429 (2014)
http://dx.doi.org/10.1364/OE.22.017423

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-14-17423

Single-cycle terahertz fields generated by coherent transition radiation from a relativistic electron beam are used to study the high field optical response of single crystal GaAs. Large amplitude changes in the sub-band-gap optical absorption are induced and probed dynamically by measuring the absorption of a broad-band optical beam generated by transition radiation from the same electron bunch, providing an absolutely synchronized pump and probe geometry. This modification of the optical properties is consistent with strong-field-induced electroabsorption. These processes are pertinent to a wide range of nonlinear terahertz-driven light-matter interactions anticipated at accelerator-based sources.

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