Title :
Giant AC Stark shift in germanium
Author :
Kolata, K. ; Köster, N. ; Woscholski, R. ; Lange, C. ; Chatterjee, S. ; Isella, G. ; Chrastina, D. ; Von Känel, H.
Author_Institution :
Fac. of Phys. & Mater. Sci. Center, Philipps-Univ. Marburg, Marburg, Germany
Abstract :
We observe a strong ultrafast AC Stark shift of the direct band transition in strained germanium quantum wells grown on silicon. At 150 meV, the maximum measured blue shift of the band edge is one order of magnitude larger than typically found in III-V materials. The power dependence shows a linear behavior between the electrical field intensity and the magnitude of the shift which is in good agreement with a dressed-exciton model. The coherent excitation dynamics in germanium are thus mainly governed by the direct transitions.
Keywords :
Stark effect; elemental semiconductors; excitons; germanium; high-speed optical techniques; semiconductor quantum wells; spectral line shift; Ge; Si; blue shift; coherent excitation dynamics; direct band transition; dressed-exciton model; electrical field intensity; electron volt energy 150 meV; silicon substrate; strained germanium quantum wells; strong ultrafast AC Stark shift; Absorption; Optical pumping; Photonics; Silicon; Stimulated emission; Temperature measurement;
Conference_Titel :
Lasers and Electro-Optics (CLEO), 2011 Conference on
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4577-1223-4
