Spin-dependent directional emission from a quantum dot ensemble embedded in an asymmetric waveguide

Wenbo Lin, Yasutomo Ota, Satoshi Iwamoto, Yasuhiko Arakawa

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


In this study, we examine a photonic wire waveguide embedded with an ensemble of quantum dots (QDs) that directionally emits into the waveguide depending on the spin state of the ensemble. The directional emission is facilitated by the spin-orbit interaction of light. The waveguide has a two-step stair-like cross section and QDs are embedded only in the upper step, such that the circular polarization of emission from the spin-polarized QDs controls the direction of the radiation. We numerically verify that more than 70% of the radiation from the ensemble emitter is toward a specific direction in the waveguide. We also examine a microdisk resonator with a stair-like edge, which supports selective coupling of the QD ensemble radiation into a whispering gallery mode that rotates unidirectionally. Our study provides a foundation for spin-dependent optoelectronic devices.

Original languageEnglish
Pages (from-to)3749-3752
Number of pages4
JournalOptics Letters
Issue number15
Publication statusPublished - 2019 Aug 1
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


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