Disorder effects in subwavelength grating metamaterial waveguides

0484771 - ÚFE 2018 RIV US eng J - Journal Article
Ortega-Moñux, A. - Čtyroký, Jiří - Cheben, P. - Schmid, J. H. - Wang, S. - Molina-Fernández, I. - Halíř, R.
Disorder effects in subwavelength grating metamaterial waveguides.
Optics Express. Roč. 25, č. 11 (2017), s. 12222-12236. ISSN 1094-4087
R&D Projects: GA ČR(CZ) GA16-00329S
Institutional support: RVO:67985882
Keywords : Subwavelength grating * Integrated photonics * Diffraction effects
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 3.356, year: 2017

Subwavelength grating (SWG) waveguides are integrated photonic structures with a pitch substantially smaller than wavelength for which they are designed, so that diffraction effects are suppressed. SWG operates as an artificial metamaterial with an equivalent refractive index which depends on the geometry of the structure and the polarization of the propagating wave. SWG waveguides have been advantageously used in silicon photonics, resulting in significant performance improvements for many practical devices, including highly efficient fiber-chip couplers, waveguide crossings, broadband multimode interference (MMI) couplers, evanescent field sensors and polarization beam splitters, to name a few. Here we present a theoretical and experimental study of the influence of disorder effects in SWG waveguides. We demonstrate via electromagnetic simulations and experimental measurements that even a comparatively small jitter (similar to 5 nm) in the position and size of the SWG segments may cause a dramatic reduction in the transmittance for wide (multimode) SWG waveguides, while for narrow (single mode) waveguides this effect is negligible. Our study shows that the impact of the jitter on SWG waveguide performance is directly related to the modal confinement
Permanent Link: http://hdl.handle.net/11104/0279920