Terahertz light-emitting graphene-channel transistor toward single-mode lasing

  • Deepika Yadav, Gen Tamamushi, Takayuki Watanabe, Junki Mitsushio, Youssef Tobah, Kenta Sugawara, Alexander A. Dubinov, Akira Satou, Maxim Ryzhii, Victor Ryzhii, Taiichi Otsuji
  • Nanophotonics, February 2018, De Gruyter
  • DOI: 10.1515/nanoph-2017-0106

Graphene transistors work for terahertz LED and laser devices

What is it about?

A transistor made with an atomically-thin monolayer sheet of graphene driven by dry-cell battery enables light-emission like light-emitting diodes (LEDs) as well as lasers in an unexplored terahertz frequency region. Researchers theoretically discovered in 2007, first, and now demonstrated real device operation after a decade.

Why is it important?

Quantum cascade laser is the only one operating in the terahertz frequency range as an integrated solid-state coherent light-source chip driven by dry-cell battery, but suffers from phonon decoherency preventing from room temperature operation. The novel material of graphene and its extraordinary optoelectronic properties can break through such a substantial limitation in existing technology. The key is the suppression of Auger processes, a killer for gain, by current-injection pumping that can effectively prevent from carrier heating. This paper demonstrates the feasibility and the potentiality of graphene as a terahertz integrated solid-state light-source device at 100K. The authors also address the ways towards room-temperature intense lasing operation.


Taiichi Otsuji
Tohoku Daigaku

Improvements on the laser cavity structure with surface plasmon-polaritonic higher photon-field confinements and higher gain overlapping will enable drastic increase in the terahertz gain leading to room-temperature intense laser operation in the terahertz frequency range.

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The following have contributed to this page: Taiichi Otsuji

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