TY - GEN
T1 - Characterisation of InAs:GaAs quantum dot-based photoconductive THz antennas
AU - Leyman, R.
AU - Carnegie, D.
AU - Bazieva, N.
AU - Molis, G.
AU - Arlauskas, A.
AU - Krotkus, A.
AU - Schulz, S.
AU - Reardon, C.
AU - Clarke, E.
AU - Rafailov, E. U.
PY - 2013/11/7
Y1 - 2013/11/7
N2 - The THz optoelectronics field is now beginning to mature and semiconductor-based THz signal emitter/detector devices are becoming more widely implemented as analytical tools in spectroscopy and imaging1. The predominant area of development in this field has always been the photoconductive (PC) active material which forms the basis of the necessary ultrafast switching process. These materials traditionally are optically pumped using, for example, a Ti:Sapphire laser which can generate ultrashort pulses with photonic energy higher than the active material bandgap. This allows the generation of (photo)carrier pairs which are accelerated by the E-field of an integrated antenna electrode pair and then captured over ultrashort timescales (τc < 1ps) usually by defects and trapping sites throughout the active material lattice. As a defective material (such as low-temperature-grown GaAs, 'LT-GaAs') is typically used, many parameters such as carrier mobility and PC gain are greatly compromised. It has been shown previously that quantum dots (QDs) deposited within or over GaAs can enable and/or enhance the efficiency of THz signal generation2. We demonstrate here the efficient generation of THz output signals using PC THz antennas based on semiconductor structures comprised of InAs quantum dots (QDs) embedded in high quality crystalline GaAs, whereby the embedded QDs act as the ultrafast capture mechanism3.
AB - The THz optoelectronics field is now beginning to mature and semiconductor-based THz signal emitter/detector devices are becoming more widely implemented as analytical tools in spectroscopy and imaging1. The predominant area of development in this field has always been the photoconductive (PC) active material which forms the basis of the necessary ultrafast switching process. These materials traditionally are optically pumped using, for example, a Ti:Sapphire laser which can generate ultrashort pulses with photonic energy higher than the active material bandgap. This allows the generation of (photo)carrier pairs which are accelerated by the E-field of an integrated antenna electrode pair and then captured over ultrashort timescales (τc < 1ps) usually by defects and trapping sites throughout the active material lattice. As a defective material (such as low-temperature-grown GaAs, 'LT-GaAs') is typically used, many parameters such as carrier mobility and PC gain are greatly compromised. It has been shown previously that quantum dots (QDs) deposited within or over GaAs can enable and/or enhance the efficiency of THz signal generation2. We demonstrate here the efficient generation of THz output signals using PC THz antennas based on semiconductor structures comprised of InAs quantum dots (QDs) embedded in high quality crystalline GaAs, whereby the embedded QDs act as the ultrafast capture mechanism3.
UR - http://www.scopus.com/inward/record.url?scp=84892759175&partnerID=8YFLogxK
UR - https://ieeexplore.ieee.org/document/6656615
U2 - 10.1109/IPCon.2013.6656615
DO - 10.1109/IPCon.2013.6656615
M3 - Conference publication
AN - SCOPUS:84892759175
SN - 9781457715075
T3 - 2013 IEEE Photonics Conference
SP - 418
EP - 419
BT - 2013 IEEE Photonics Conference, IPC 2013
PB - IEEE
T2 - 2013 26th IEEE Photonics Conference, IPC 2013
Y2 - 8 September 2013 through 12 September 2013
ER -