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Organization / Research

Otuji Laboratory


photo Taiichi OTSUJI, Professor
Tetsuya SUEMITSU, Associate Professor
Akira SATO, Assistant Professor

Newly-proposed plasmon-resonant emitter/photomixer operating in the terahertz range.
(Upper: cross-sectional view and SEM images of the first sample fabricated with GaAs-based heterostructure material systems,
Middle: Simulated instantaneous electric field distribution under continuous plasmon excitation at 5.1 THz,
Lower: FTIR-measured broadband emission spectra in the self-oscillation mode)

Terahertz (sub-millimeter) coherent electromagnetic waves are expected to diversify the potential applications of imaging, spectroscopy, as well as communications technologies. The terahertz band, however, is still an unexplored region in the sense that no practical integrated device technology exists. This is because conventional electron devices as well as photonic devices face to the substantial limit of operation. That is the motivation of our research.

We are developing novel, integrated electron devices and circuit systems operating in the millimeter-wave and terahertz regions with functionalities of coherent, tunable signal generation and ultra-broadband signal processing. One example is a frequency-tunable plasmon-resonant terahertz emitter/photomixer. Based on both experimental and theoretical investigation on plasmon resonance for heterostructure devices, we have developed a novel device structure that can drastically improve the radiation power and frequency tunability, which has recently succeeded in terahertz emission of radiation at room temperature. Another example is a unique electromagnetic metamaterial circuit systems based on optoelectronic dispersion control of low-dimensional plasmons. We are also pursuing graphene-based new materials and original device structures for ultrafast transistors as well as terahertz lasers to break through the limit on conventional transistor speed and lasing frequency.

By making full use of those devices and circuits, we are exploring new applications including future smart photonic network systems as well as millimeter-wave- and terahertz-band spectroscopic measurement systems.

Research topics:

  1. Millimeter-wave and terahertz integrated microelectronic devices and circuits
  2. Plasmon-resonant terahertz emitters/photomixers
  3. Electromagnetic metamaterial circuit systems based on dispersion control of low-dimensional plasmons
  4. Graphene-based ultimate ultrafast transistors and terahertz lasers
  5. Application of THz integrated microelectronics to the future communications and measurement systems
Group of Electrical Engineering, Communication Engineering,
Electronic Engineering, and Information Engineering, Tohoku University
6-6-05, Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
TEL : 022-795-7186 (Japanese Only)
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