Sub-femtojoule all-optical switching using a photonic-crystal nanocavity

Kengo Nozaki, Takasumi Tanabe, Akihiko Shinya, Shinji Matsuo, Tomonari Sato, Hideaki Taniyama, Masaya Notomi

Research output: Contribution to journalArticlepeer-review

616 Citations (Scopus)


Although high-speed all-optical switches are expected to replace their electrical counterparts in information processing, their relatively large size and power consumption have remained obstacles. We use a combination of an ultrasmall photonic-crystal nanocavity and strong carrier-induced nonlinearity in InGaAsP to successfully demonstrate low-energy switching within a few tens of picoseconds. Switching energies with a contrast of 3 and 10dB of 0.42 and 0.66fJ, respectively, have been obtained, which are over two orders of magnitude lower than those of previously reported all-optical switches. The ultrasmall cavity substantially enhances the nonlinearity as well as the recovery speed, and the switching efficiency is maximized by a combination of two-photon absorption and linear absorption in the InGaAsP nanocavities. These switches, with their chip-scale integratability, may lead to the possibility of low-power, high-density, all-optical processing in a chip.

Original languageEnglish
Pages (from-to)477-483
Number of pages7
JournalNature Photonics
Issue number7
Publication statusPublished - 2010 Jul
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


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