Abstract-Cost-efficient delay generator for fast terahertz imaging

T. Probst, A. Rehn, S. F. Busch, S. Chatterjee, M. Koch, and M. Scheller  »View Author Affiliations

Optics Letters, Vol. 39, Issue 16, pp. 4863-4866 (2014)
http://dx.doi.org/10.1364/OL.39.004863

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-16-4863

We present a fast and low-cost delay generator for terahertz (THz) waves that transfers a rotational motion of a transparent dielectric cube into an effective THz delay. The device is easily implemented in the THz beam path and allows for coherent sampling over 40 ps with a scan rate of hundreds of hertz. Furthermore, we show that our approach is particularly suitable for fast THz imaging.

© 2014 Optical Society of America

Abstract:Ionization of coherent excitons by strong terahertz fields

B. Ewers, N. S. Köster, R. Woscholski, M. Koch, and S. Chatterjee 
Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany

G. Khitrova and H. M. Gibbs 
College of Optical Sciences, The University of Arizona, 1630 E. University Boulevard, Tucson, Arizona 85719-0094, USA

A. C. Klettke, M. Kira, and S. W. Koch 
Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, Mainzer Gasse 33, D-35032 Marburg, Germany

Received 7 December 2011; revised 16 January 2012; published 6 February 2012

The interaction of coherent excitons with intense, single-cycle terahertz (THz) pulses is investigated. A significant bleaching of the 1s-exciton resonance develops into a splitting of the absorption peak and the emergence of pronounced wings with increasing THz field strength. A quantum-mechanical many-body analysis attributes the experimental observations to a transition from excitonic Rabi flopping to multi-THz-photon ionization and the population of optically dark exciton states with high quantum numbers.

©2012 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevB.85.075307

DOI:

10.1103/PhysRevB.85.075307

PACS:

78.67.De, 42.65.Re, 78.47.D-