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Nature 417, 156-159 (9 May 2002) | doi:10.1038/417156a; Received 14 January 2002; Accepted 19 February 2002

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Terahertz semiconductor-heterostructure laser

Rüdeger Köhler1, Alessandro Tredicucci1, Fabio Beltram1, Harvey E. Beere2, Edmund H. Linfield2, A. Giles Davies2, David A. Ritchie2, Rita C. Iotti3 & Fausto Rossi3

  1. NEST-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
  2. Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
  3. INFM and Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy

Correspondence to: Rüdeger Köhler1 Correspondence and requests for materials should be addressed to R.K. (e-mail: Email: koehler@nest.sns.it.).

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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.

  1. NEST-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
  2. Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
  3. INFM and Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy

Correspondence to: Rüdeger Köhler1 Correspondence and requests for materials should be addressed to R.K. (e-mail: Email: koehler@nest.sns.it.).