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Yasuhiko Ishkawa

Affiliation Department of Electrical and Electronic Information Engineering
Title Professor
Fields of Research Semiconductor Devices, Silicon Photonics
Degree Ph.D. (Hokkaido University)
Academic Societies Japan Society of Applied Physics, IEEE, SPIE, MRS, ECS
E-mail ishikawa@ee
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Laboratory website URL
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Silicon photonics is a technology to integrate ultrasmall photonic devices on a Si chip using LSI processes. Such integrated photonic devices are strongly required for low-power and high-capacity information transmission. High-preformance active photonic devices operating at the near-infrared communication wavelengths (1.3-1.6 µm) are integrated on a Si chip with passive photonic devices such as optical waveguides and optical filters. Based on state-of-the-art SiGe epitaxial growth technology, novel photonic devices using group-IV epitaxial layers on Si are proposed and realized.

Theme1:Si-based Waveguides


Si/Si nitride waveguides enable light propagation on a Si chip for high-capacity optical communications (wavelength: 1.3 - 1.6 µm) as well as optical interconnections in high-performance LSIs such as AI chips. Photonic integration chips are fabricated on standard bulk Si wafers as well as SOI (Si-on-insulator) wafers.

Theme2:Ge-on-Si Photodetectors


Photodetectors are inevitably necessary to convert optical signals to electrical ones for the processing with LSIs. Ge, a group-IV semiconductor similar to Si, has a good compatibility with Si processing technology. Integrated photodetectors of high-quality Ge epitaxial layer have been realized.

Theme3:Novel Ge-on-Si Devices


Ge is an indirect bandgap semiconductor, while theoretical investigations have shown that excellent optical properties, similar to direct semiconductors, can be obtained applying the band engineering. Novel photonic devices are under investigations such as optical intensity/phase modulators and light emitters (particularly, lasers).

Title of class

Analytical Electromagnetism II
Electromagnetic Wave Engineering
Engineering and Science Laboratory
Quantum Optoelectronics

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