RQC Seminar

50th RQC Seminar

• Speaker

  Mr. Yuma Kawaguchi
  ( The City College of New York, USA. Ph.D. Student )

• Date

  15:00 - 16:00 (JST), June 2, 2023 (Friday)

• Venue

  Hybrid(ZOOM・ Wako Main Research 3F 345-347 Seminar Room)

• Title

  Non-reciprocal optical response in ring resonators integrated with magneto-optical materials and transition metal dichalcogenides

• Inquiries

  rqc_info[at]ml.riken.jp

Abstract
The traditional approach to create an optical isolator requires applying an external magnetic field to magneto-optical (MO) materials, which provides a large dichroic response at certain wavelength range. However, the need of external magnetic field and use of MO materials prevents minimization and fabrication in CMOS process, at the same time, their large circular dichroism in low loss regime limits the applications of most ferrite materials. In this talk, we will explore new approaches for non-reciprocal optical response using MO materials and transition metal dichalcogenides (TMDs). Our analytic model explains that the dichroic absorption in MO materials, which has been avoided due to their large loss, can be used in a different approach based on critical coupling condition in a ring resonator. Also, we propose that the non-reciprocal response in optically biased TMD monolayer and we develop an analytic model to understand non-reciprocity occurred by biased exciton populations. The results of the study will broaden the choices of materials and operation wavelengths.

Reference: Sriram Guddala, Yuma Kawaguchi, Filipp Komissarenko, Svetlana Kiriushechkina, Anton Vakulenko, Kai Chen, Andrea Alù, Vinod M. Menon and Alexander B. Khanikaev, “All-optical nonreciprocity due to valley polarization pumping in transition metal dichalcogenides”, Nature Communications 12, 3746 (2021).