THz quantum-confined Stark effect in semiconductor quantum dots

Dmitry Turchinovich, Boris S. Monozon, Daniil A. Livshits, Edik U. Rafailov, Matthias C. Hoffmann

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    We demonstrate an instantaneous all-optical manipulation of optical absorption at the ground state of InGaAs/GaAs quantum dots (QDs) via a quantum-confined Stark effect (QCSE) induced by the electric field of incident THz pulses with peak electric fields reaching 200 kV/cm in the free space. As a result, a THz signal with the full bandwidth of 3 THz can be directly encoded onto an optical signal probing the ground state absorption in QDs, resulting in the encoded temporal features as fast as 460 fs. The optical absorption modulation at highest THz fields reaches about 30% of the total optical absorption in QDs at the ground state. The dependency of electro-absorption modulation depth on the peak THz field is found to be strongly nonlinear, as expected from the QCSE. From this dependency we conclude that the dominant contribution to the observed electro-absorption modulation in our sample is made by the overall optical absorption quenching via a reduction of the overlap integral and hence the probability of inter-band transition, rather than by the Stark shift of the QD absorption peak away from the spectrum of the optical probe. As expected from the three-dimensional geometry of a QD, the THz QCSE was found to be independent of the polarization of the THz field. The instantaneous nature of THz QCSE in QDs enables femtosecond all-optical switching at very high repetition rates. This allowed us to demonstrate the potential for applications in THz-range wireless communication systems with the data rate of at least 0.5 Tbit/s.
    Original languageEnglish
    Title of host publicationUltrafast Phenomena and Nanophotonics XVI
    EditorsMarkus Betz, Abdulhakem Y. Elezzabi, Jin-Joo Song, Kong-Thon Tsen
    Place of PublicationBellingham
    PublisherSPIE-International Society for Optical Engineering
    ISBN (Print)9780819489036
    DOIs
    Publication statusPublished - 2012
    EventSPIE Photonics West 2012: Ultrafast Phenomena and Nanophotonics XVI - The Moscone Center, San Francisco, United States
    Duration: 22 Jan 201225 Jan 2012

    Publication series

    NameProceedings of SPIE
    PublisherSPIE
    Volume8260

    Conference

    ConferenceSPIE Photonics West 2012: Ultrafast Phenomena and Nanophotonics XVI
    Abbreviated titlehttp://spie.org/x85481.xml
    CountryUnited States
    CitySan Francisco
    Period22/01/1225/01/12

    Fingerprint Dive into the research topics of 'THz quantum-confined Stark effect in semiconductor quantum dots'. Together they form a unique fingerprint.

  • Cite this

    Turchinovich, D., Monozon, B. S., Livshits, D. A., Rafailov, E. U., & Hoffmann, M. C. (2012). THz quantum-confined Stark effect in semiconductor quantum dots. In M. Betz, A. Y. Elezzabi, J-J. Song, & K-T. Tsen (Eds.), Ultrafast Phenomena and Nanophotonics XVI [826003] (Proceedings of SPIE; Vol. 8260). SPIE-International Society for Optical Engineering. https://doi.org/10.1117/12.906448