Skip to main content
Log in

Terahertz semiconductor-heterostructure laser

  • Letter
  • Published:

From Nature

View current issue Submit your manuscript

Abstract

Semiconductor devices have become indispensable for generating electromagnetic radiation in everyday applications. Visible and infrared diode lasers are at the core of information technology, and at the other end of the spectrum, microwave and radio-frequency emitters enable wireless communications. But the terahertz region (1–10 THz; 1 THz = 1012 Hz) between these ranges has remained largely underdeveloped, despite the identification of various possible applications—for example, chemical detection, astronomy and medical imaging1,2,3,4. Progress in this area has been hampered by the lack of compact, low-consumption, solid-state terahertz sources5,6,7,8,9. Here we report a monolithic terahertz injection laser that is based on interminiband transitions in the conduction band of a semiconductor (GaAs/AlGaAs) heterostructure. The prototype demonstrated emits a single mode at 4.4 THz, and already shows high output powers of more than 2 mW with low threshold current densities of about a few hundred A cm-2 up to 50 K. These results are very promising for extending the present laser concept to continuous-wave and high-temperature operation, which would lead to implementation in practical photonic systems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Figure 1: Conduction band structure of the laser active core and computed population inversion and current density at several applied biases.
Figure 2: Waveguide design principle and radiation mode confinement.
Figure 3: Emission spectra from a 1.24-mm-long and 180-µm-wide laser device recorded at 8 K for different drive currents.
Figure 4: Light–current (LI) characteristics of a 180-µm-wide and 3.1-mm-long laser ridge.

Similar content being viewed by others

References

  1. Miles, R. E., Harrison, P. & Lippens, D. (eds) Terahertz Sources and Systems Vol. 27 (NATO Science Series II, Kluwer, Dordrecht, 2001)

  2. Han, P. Y., Cho, G. C. & Zhang, X.-C. Time-domain transillumination of biological tissue with terahertz pulses. Opt. Lett. 25, 242–244 (2000)

    Article  ADS  CAS  Google Scholar 

  3. Mittleman, D. M., Jacobsen, R. H. & Nuss, M. C. T-ray imaging. IEEE J. Sel. Top. Quant. Electron. 2, 679–692 (1996)

    Article  ADS  CAS  Google Scholar 

  4. Mittleman, D. M., Hunsche, S., Boivin, L. & Nuss, M. C. T-ray tomography. Opt. Lett. 22, 904–906 (1997)

    Article  ADS  CAS  Google Scholar 

  5. Pavlov, S. G. et al. Stimulated emission from donor transitions in silicon. Phys. Rev. Lett. 84, 5220–5223 (2000)

    Article  ADS  CAS  Google Scholar 

  6. Matsuura, S., Tani, M. & Sakai, K. Generation of coherent terahertz radiation by photomixing in dipole photoconductive antennas. Appl. Phys. Lett. 70, 559–561 (1997)

    Article  ADS  CAS  Google Scholar 

  7. Hu, B. B., Zhang, X.-C. & Auston, D. H. Terahertz radiation induced by subband-gap femtosecond optical excitation of GaAs. Phys. Rev. Lett. 67, 2709–2712 (1991)

    Article  ADS  CAS  Google Scholar 

  8. Kersting, R., Unterrainer, K., Strasser, G., Kauffmann, H. F. & Gornik, E. Few-cycle THz emission from cold plasma oscillations. Phys. Rev. Lett. 79, 3038–3041 (1997)

    Article  ADS  CAS  Google Scholar 

  9. Bründermann, E., Chamberlin, D. R. & Haller, E. E. High duty cycle and continuous terahertz emission from germanium. Appl. Phys. Lett. 76, 2991–2993 (2000)

    Article  ADS  Google Scholar 

  10. Faist, J. et al. Quantum cascade laser. Science 264, 553–556 (1994)

    Article  ADS  CAS  Google Scholar 

  11. Rochat, M., Faist, J., Beck, M., Oesterle, U. & Ilegems, M. Far-infrared (λ = 88 µm) electroluminescence in a quantum cascade structure. Appl. Phys. Lett. 73, 3724–3726 (1998)

    Article  ADS  CAS  Google Scholar 

  12. Williams, B. S., Xu, B., Hu, Q. & Melloch, M. R. Narrow-linewidth terahertz intersubband emission from three-level systems. Appl. Phys. Lett. 75, 2927–2929 (1999)

    Article  ADS  CAS  Google Scholar 

  13. Ulrich, J., Zobl, R., Schrenk, W., Strasser, G. & Unterrainer, K. Terahertz quantum cascade structures: Intra- versus interwell transition. Appl. Phys. Lett. 76, 1928–1930 (2000)

    Article  ADS  Google Scholar 

  14. Helm, M., England, P., Colas, E., De Rosa, F. & Allen, S. J. Intersubband emission from semiconductor superlattices excited by sequential resonant tunnelling. Phys. Rev. Lett. 63, 74–77 (1989)

    Article  ADS  CAS  Google Scholar 

  15. Colombelli, R. et al. Far-infrared surface-plasmon quantum-cascade lasers at 21.5 µm and 24 µm wavelengths. Appl. Phys. Lett. 78, 2620–2622 (2001)

    Article  ADS  CAS  Google Scholar 

  16. Hofstetter, D., Beck, M., Aellen, T. & Faist, J. High-temperature operation of distributed feedback quantum-cascade lasers at 5.3 µm. Appl. Phys. Lett. 78, 396–398 (2001)

    Article  ADS  CAS  Google Scholar 

  17. Köhler, R., Iotti, R. C., Tredicucci, A. & Rossi, F. Design and simulation of terahertz quantum cascade lasers. Appl. Phys. Lett. 79, 3920–3922 (2001)

    Article  ADS  Google Scholar 

  18. Tredicucci, A. et al. High performance interminiband quantum cascade lasers with graded superlattices. Appl. Phys. Lett. 73, 2101–2103 (1998)

    Article  ADS  CAS  Google Scholar 

  19. Iotti, R. C. & Rossi, F. Nature of charge transport in quantum-cascade lasers. Phys. Rev. Lett. 87, 146603-1–146603-4 (2001)

    Article  ADS  Google Scholar 

  20. Iotti, R. C. & Rossi, F. Carrier thermalization versus phonon-assisted relaxation in quantum-cascade lasers: A Monte Carlo approach. Appl. Phys. Lett. 78, 2902–2904 (2001)

    Article  ADS  CAS  Google Scholar 

  21. Sirtori, C. et al. Long-wavelength (λ∼8–11.5 µm) semiconductor lasers with waveguides based on surface plasmons. Opt. Lett. 23, 1366–1368 (1998)

    Article  ADS  CAS  Google Scholar 

  22. Rochat, M., Beck, M., Faist, J. & Oesterle, U. Measurement of far-infrared waveguide loss using a multisection single-pass technique. Appl. Phys. Lett. 78, 1967–1969 (2001)

    Article  ADS  CAS  Google Scholar 

  23. Köhler, R. et al. High-intensity interminiband terahertz emission from chirped superlattices. Appl. Phys. Lett. 80, 1867 (2002)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank S. Dhillon for discussions.This work was supported in part by the European Commission through the IST Framework V FET project WANTED. R.K. was supported by the C.N.R.; E.H.L. and A.G.D were supported by Toshiba Research Europe Ltd and The Royal Society, respectively.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Rüdeger Köhler.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Köhler, R., Tredicucci, A., Beltram, F. et al. Terahertz semiconductor-heterostructure laser. Nature 417, 156–159 (2002). https://doi.org/10.1038/417156a

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/417156a

  • Springer Nature Limited

This article is cited by

Navigation