Plasmonic all-optical tunable wavelength shifter

• Published in: Nature photonics Vol. 1; no. 12; pp. 701 - 703
• Main Authors: Fluegel, B, Mascarenhas, A, Snoke, D. W, Pfeiffer, L. N, West, K
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01-12-2007
• Subjects: Wavelengths
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2007.229

At present, wavelength-division-multiplexed fibre lines routinely operate at 10 Gbit s-1 per channel. The transition from static-path networks to true all-optical networks encompassing many nodes, in which channels are added/dropped and efficiently reassigned, will require improved tools for all-optical wavelength shifting. Specifically, one must be able to shift the carrier wavelength (frequency) of an optical data signal over tens of nanometres (a THz range) without the bottleneck of electrical conversion. Popular approaches to this problem make use of the nonlinear interaction between two wavelengths within a semiconductor optical amplifier whereas more novel methods invoke terahertz-frequency electro-optic modulation and polaritons. Here we outline the principles and demonstrate the use of optically excited plasmons as a tunable frequency source that can be mixed with a laser frequency through Raman scattering. The scheme is all-optical and enables dynamical control of the output carrier wavelength simply by varying the power of a control laser.