Prof. Hideki Yokoi
Shibaura Institute of Technology, Japan

Speech Title: Waveguide-type Optical Nonreciprocal Devices for Si Photonics

Abstract: In optical communication systems, optical nonreciprocal devices, such as optical isolators or optical circulators, are indispensable in protecting active photonic devices from unwanted reflected light. In the near infrared region, magnetic garnet crystals are necessary for constructing optical nonreciprocal devices owing to their transparency and large magneto-optic coefficient. The author has investigated an interferometric optical isolator by using a nonreciprocal phase shift. The nonreciprocal phase shift occurs in transverse magnetic modes that travel in magneto-optic waveguides in which magnetization is aligned transverse to the light propagation direction in the film plane. The optical isolator employing the nonreciprocal phase shift is attractive because there is no need for phase matching or complicated control of the direction of magnetization. The author’s group demonstrated the nonreciprocal phase shift in the magneto-optic waveguide with a magnetic garnet guiding layer. The author’s group also demonstrated the nonreciprocal phase shift in the magneto-optic waveguide with a GaInAsP guiding layer fabricated by wafer bonding technique. In 2003, the author proposed an optical isolator with a Si guiding layer. Since then, many research groups have investigated optical isolators with a Si guiding layer for Si photonics. The author introduces waveguide-type optical isolators employing the nonreciprocal phase shift. Calculated nonreciprocal phase shifts of magneto-optic waveguides with various layer structures are discussed.

Bio: Hideki Yokoi received the B.E. (1989), M.E. (1991), and D.E. (2000) degrees in physical electronics from Tokyo Institute of Technology. He is a professor, College of Engineering, Shibaura Institute of Technology. His current interests include optical nonreciprocal devices, photonic integrated circuits, optical fiber sensors, and optofluidic sensors.

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