Four-wave mixing in slow light photonic crystal waveguides with very high group index

Juntao Li*, Liam O'Faolain, Thomas F. Krauss

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)
1 Downloads (Pure)


We report efficient four-wave mixing in dispersion engineered slow light silicon photonic crystal waveguides with a flat band group index of n(g) = 60. Using only 15 mW continuous wave coupled input power, we observe a conversion efficiency of -28 dB. This efficiency represents a 30 dB enhancement compared to a silicon nanowire of the same length. At higher powers, thermal redshifting due to linear absorption was found to detune the slow light regime preventing the expected improvement in efficiency. We then overcome this thermal limitation by using oxide-clad waveguides, which we demonstrate for group indices of n(g) = 30. Higher group indices may be achieved with oxide clad-waveguides, and we predict conversion efficiencies approaching -10 dB, which is equivalent to that already achieved in silicon nanowires but for a 50x shorter length.

Original languageEnglish
Pages (from-to)17474-17479
Number of pages6
JournalOptics Express
Issue number16
Publication statusPublished - 30 Jul 2012


  • Enhancement
  • Generation
  • Silicon
  • Dispersion


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