Here we overview our work on quantum dot based THz photoconductive antennae, capable of being pumped at very high optical intensities of higher than 1W optical mean power, i.e. about 50 times higher than the conventional LT-GaAs based antennae. Apart from high thermal tolerance, defect-free GaAs crystal layers in an InAs:GaAs quantum dot structure allow high carrier mobility and ultra-short photo carrier lifetimes simultaneously. Thus, they combine the advantages and lacking the disadvantages of GaAs and LT-GaAs, which are the most popular materials so far, and thus can be used for both CW and pulsed THz generation. By changing quantum dot size, composition, density of dots and number of quantum dot layers, the optoelectronic properties of the overall structure can be set over a reasonable range-compact semiconductor pump lasers that operate at wavelengths in the region of 1.0 μm to 1.3 μm can be used. InAs:GaAs quantum dot-based antennae samples show no saturation in pulsed THz generation for all average pump powers up to 1W focused into 30 μm spot. Generated THz power is super-linearly proportional to laser pump power. The generated THz spectrum depends on antenna design and can cover from 150 GHz up to 1.5 THz.
|Title of host publication||Synthesis and Photonics of Nanoscale Materials XIII|
|Editors||Andrei V. Kabashin, David B. Geohegan, Jan J. Dubowski|
|Place of Publication||Bellingham, WA (US)|
|Number of pages||9|
|Publication status||Published - 9 Mar 2016|
|Event||Synthesis and Photonics of Nanoscale Materials XIII - San Francisco, United States|
Duration: 15 Feb 2016 → 17 Feb 2016
|Conference||Synthesis and Photonics of Nanoscale Materials XIII|
|Period||15/02/16 → 17/02/16|
Bibliographical noteAndrei Gorodetsky; Natalia Bazieva and Edik U. Rafailov; "Quantum-dot based ultrafast photoconductive antennae for efficient THz radiation", Proc. SPIE 9737, Synthesis and Photonics of Nanoscale Materials XIII, 97370C (March 9, 2016).
Copyright 2016. Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited
Funding: EPSRC Grant No EP/H015795/1 and FP7 IAPP TERA project No 285974
- photoconductive antenna
- quantum dots
- THz generation