Quantum dot-based terahertz photoconductive antennas

Andrei Gorodetsky, Edik U. Rafailov, Ross Leyman

Research output: Chapter in Book/Report/Conference proceedingConference publication


We present novel Terahertz (THz) emitting optically pumped Quantum Dot (QD) photoconductive (PC) materials and antenna structures on their basis both for pulsed and CW pumping regimes.

Full text

Quantum dot and microantenna design - Presented here are design considerations for the semiconductor materials in our novel QD-based photoconductive antenna (PCA) structures, metallic microantenna designs, and their implementation as part of a complete THz source or transceiver system.
Layers of implanted QDs can be used for the photocarrier lifetime shortening mechanism[1,2]. In our research we use InAs:GaAs QD structures of varying dot layer number and distributed Bragg reflector(DBR)reflectivity range. According to the observed dependence of carrier lifetimes on QD layer periodicity [3], it is reasonable to assume that electron lifetimes can be potentially reduced down to 0.45ps in such structures. Both of these features; long excitation wavelength and short carriers lifetime predict possible feasibility of QD antennas for THz generation and detection.
In general, relatively simple antenna configurations were used here, including: coplanar stripline (CPS); Hertzian-type dipoles; bow-ties for broadband and log-spiral(LS)or log-periodic(LP)‘toothed’ geometriesfor a CW operation regime.

Experimental results - Several lasers are used for antenna pumping: Ti:Sapphire femtosecond laser, as well as single-[4], double-[5] wavelength, and pulsed [6] QD lasers. For detection of the THz signal different schemes and devices were used, e.g. helium-cooled bolometer, Golay cell and a second PCA for coherent THz detection in a traditional time-domain measurement scheme.Fig.1shows the typical THz output power trend from a 5 um-gap LPQD PCA pumped using a tunable QD LD with optical pump spectrum shown in (b).

Summary - QD-based THz systems have been demonstrated as a feasible and highly versatile solution. The implementation of QD LDs as pump sources could be a major step towards ultra-compact, electrically controllable transceiver system that would increase the scope of data analysis due to the high pulse repetition rates of such LDs [3], allowing real-time THz TDS and data acquisition. Future steps in development of such systems now lie in the further investigation of QD-based THz PCA structures and devices, particularly with regards to their compatibilitywith QD LDs as pump sources.

[1]E. U. Rafailov et al., “Fast quantum-dot saturable absorber for passive mode-locking of solid-State lasers,”Photon.Tech.Lett., IEEE, vol. 16 pp. 2439-2441(2004)
[2]E. Estacio, “Strong enhancement of terahertz emission from GaAs in InAs/GaAs quantum dot structures. Appl.Phys.Lett., vol. 94 pp. 232104 (2009)
[3]C. Kadow et al., “Self-assembled ErAs islands in GaAs: Growth and subpicosecond carrier dynamics,” Appl. Phys. Lett., vol. 75 pp. 3548-3550 (1999)
[4]T. Kruczek, R. Leyman, D. Carnegie, N. Bazieva, G. Erbert, S. Schulz, C. Reardon, and E. U. Rafailov, “Continuous wave terahertz radiation from an InAs/GaAs quantum-dot photomixer device,” Appl. Phys. Lett., vol. 101(2012)
[5]R. Leyman, D. I. Nikitichev, N. Bazieva, and E. U. Rafailov, “Multimodal spectral control of a quantum-dot diode laser for THz difference frequency generation,” Appl. Phys. Lett., vol. 99 (2011)
[6]K.G. Wilcox, M. Butkus, I. Farrer, D.A. Ritchie, A. Tropper, E.U. Rafailov, “Subpicosecond quantum dot saturable absorber mode-locked semiconductor disk laser, ” Appl. Phys. Lett. Vol 94, 2511

Original languageEnglish
Title of host publicationProceedings : 2014 international conference Laser Optics
Place of PublicationPiscataway, NJ (US)
Number of pages1
ISBN (Electronic)978-1-4799-3885-8
ISBN (Print)978-1-4799-3884-1
Publication statusPublished - 31 Dec 2014
Event2014 international conference Laser Optics - St. Petersburg, Russian Federation
Duration: 30 Jun 20144 Jul 2014


Conference2014 international conference Laser Optics
Abbreviated titleLO 2014
CountryRussian Federation
CitySt. Petersburg

Bibliographical note

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Funding: EU FP7 Programme (TERA) grant 285794


  • photoconductive antenna
  • quantum dot
  • terahertz generation

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  • Research Output

    • 3 Conference publication

    73 nm wavelength tuning from a frequency-doubled quantum-dot laser in PPKTP waveguides

    Fedorova, K. A., Sokolovskii, G. S., Battle, P. R., Livshits, D. A. & Rafailov, E. U., 31 Dec 2014, Proceedings : 2014 international conference Laser Optics. Piscataway, NJ (US): IEEE, 1 p.

    Research output: Chapter in Book/Report/Conference proceedingConference publication

  • Dynamical interplay between ground and excited states in quantum dot laser

    Sokolovskii, G. S., Dudelev, V. V., Kolykhalova, E. D., Deryagin, A. G., Bakoz, A., Novikov, I. I., Maximov, M. V., Zhukov, A. E., Ustinov, V. M., Kuchinskii, V. I., Sibbett, W., Rafailov, E. U., Viktorov, E. A. & Erneux, T., 31 Dec 2014, Proceedings : 2014 international conference Laser Optics. Piscataway, NJ (US): IEEE, 1 p.

    Research output: Chapter in Book/Report/Conference proceedingConference publication

  • Novel evaluation procedure for internal and extraction efficiency of high-power blue LEDs

    Titkov, I. E., Yadav, A., Zerova, V. L., Zulonas, M., Rafailov, E. U., Karpov, S. Y., Strassburg, M., Pietzonka, I., Lugauer, H-J. & Galler, B., 31 Dec 2014, Proceedings : 2014 international conference Laser Optics. Piscataway, NJ (US): IEEE, 1 p.

    Research output: Chapter in Book/Report/Conference proceedingConference publication

  • Cite this

    Gorodetsky, A., Rafailov, E. U., & Leyman, R. (2014). Quantum dot-based terahertz photoconductive antennas. In Proceedings : 2014 international conference Laser Optics IEEE. https://doi.org/10.1109/LO.2014.6886295