Research Institute of Electrical Communication Tohoku University


Hiroshi Yasaka,Professor

Masato Yoshida,Associate Professor

Nobuhide Yokota,Assistant Professor

H.Yasaka N.Yokota


Research Activities

Internet traffic has been increasing explosively and the amount of information which should be processed has been increasing. The capacity of information processing in optical communication systems should be increased drastically to cope with the explosive increase in the information traffic. It is necessary to realize ultra-high speed and highly functional semiconductor photonic devices and semiconductor photonic integrated circuits to construct next generation highly functional optical information communication network systems.
We are investigating novel, highly functional semiconductor photonic devices, which is indispensable to realize new generation optical information communication network systems. Furthermore, our research interests cover ultrafast photonic devices, opto-electronic semiconductor devices and their applications to optical computing and signal processing areas.

Laboratory Web Page

ECEI Web Page

Highly Functional Photonics(Prof. Yasaka)

Highly Functional Photonics (Prof. Yasaka)
It is indispensable to establish highly functional light source and photonic device technologies and novel functional semiconductor photonic integrated circuit technology for realizing highly functional optical communication systems and novel functional optical signal processing systems. We have been studying highly functional semiconductor photonic devices and semiconductor photonic integrated circuits based on semiconductor lasers and semiconductor optical modulators to create novel semiconductor photonic devices, which can control intensity, phase, frequency and polarization of optical signal freely. Furthermore we research novel semiconductor photonic functional devices based on novel principle to realize innovative photonic information communication network systems.

Research topics

  • Ultra-high speed control of semiconductor photonic devices by signal light injection
  • Highly functional semiconductor light sources
  • Highly functional semiconductor optical modulators
  • Novel functional semiconductor photonic integrated circuits


High accuracy optical measurement(Assoc. Prof. Yoshida)

We are engaged in the development of frequency stabilized laser operated at 1.55 μm and its application to high accuracy measurements using optical fibers. Furthermore, we are developing ultra-short pulse lasers.

Research topics

  • Frequency stabilized lasers and their application to high accuracy measurements using optical fibers
  • Ultrashort mode-locked lasers and their appli-cation to frequency standards and microwave-photonics

Schematic structure of a hybrid-modulation semiconductor laser
Negative chirp operation
optical fiber transmission characteristics of hybrid-modulation semiconductor laser