Send to:

Choose Destination
See comment in PubMed Commons below
Science. 2005 Oct 28;310(5748):651-3.

Quantum coherence in an optical modulator.

Author information

  • 1Physics Department and Institute for Quantum and Complex Dynamics (iQCD), Broida Hall Building 572, Room 3410, University of California, Santa Barbara, CA 93106, USA.


Semiconductor quantum well electroabsorption modulators are widely used to modulate near-infrared (NIR) radiation at frequencies below 0.1 terahertz (THz). Here, the NIR absorption of undoped quantum wells was modulated by strong electric fields with frequencies between 1.5 and 3.9 THz. The THz field coupled two excited states (excitons) of the quantum wells, as manifested by a new THz frequency- and power-dependent NIR absorption line. Nonperturbative theory and experiment indicate that the THz field generated a coherent quantum superposition of an absorbing and a nonabsorbing exciton. This quantum coherence may yield new applications for quantum well modulators in optical communications.

Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk