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Terahertz imaging with a highly-sensitive quantum dot detector

S. Spasov ; S. Pelling ; R. Davis ; V. Antonov ; L. V. Kulik ; Sergey Kubatkin (Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik)
21st International Symposium on Space Terahertz Technology 2010, ISSTT 2010; Oxford; United Kingdom; 23 March 2010 through 25 March 2010 p. 266. (2010)
[Konferensbidrag, refereegranskat]

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.



Denna post skapades 2016-05-13.
CPL Pubid: 236500

 

Institutioner (Chalmers)

Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik

Ämnesområden

Elektroteknik och elektronik

Chalmers infrastruktur