Terahertz imaging with a highly-sensitive quantum dot detector
Paper i proceeding, 2010

We report on an application of photon counting detector in the sub-terahertz range of electromagnetic waves for imaging of natural and stimulated radiation emitted by free standing objects. The detector is assembled from a GaAs/AlGaAs quantum dot, electron reservoir and quantum point contact (QPC). Its operation relies on photon-to-plasmon and plasmon-to-charge conversion, followed by charge measurement in a single-shot mode. Individual photons excite plasma waves in the quantum dot, with a resonance frequency determined by the shape of the QD confining potential. The plasma wave decays subsequently by single-particle electron-hole excitations, which change the electrostatic potential stepwise in the close proximity to the QD. The potential steps are probed with the QPC operating as a sensitive electrometer. A studied object is placed on a twodimensional translating stage. Its emission is projected through an optical window onto the detector attached to a 1K cold finger in a cryostat. Subsequently translating the stage in two space directions we are able to map the distribution of the emitted radiation. The presented technique has a potential for imaging of objects passively radiated in the sub-terahertz range.


S. Spasov

Royal Holloway University of London

S. Pelling

Royal Holloway University of London

R. Davis

Royal Holloway University of London

V. Antonov

Royal Holloway University of London

L. V. Kulik

Russian Academy of Sciences

Sergey Kubatkin

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

21st International Symposium on Space Terahertz Technology 2010, ISSTT 2010; Oxford; United Kingdom; 23 March 2010 through 25 March 2010



Elektroteknik och elektronik