Open AccessCharacterization of CMOS metal based dielectric loaded surface plasmon waveguides at telecom wavelengths
Author(s) -
Jean Claude Weeber,
Juan Arocas,
Olivier Heintz,
Laurent Markey,
Sviatlana Viarbitskaya,
Gérard Colas-des-Francs,
Kamal Hammani,
Alain Dereux,
Claudia Hoessbacher,
Ueli Koch,
Juerg Leuthold,
Karl Rohracher,
Anna Lena Giesecke,
Caroline Porschatis,
T. Wahlbrink,
Bartos Chmielak,
Nikos Pleros,
D. Tsiokos
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.000394
Subject(s) - materials science , surface plasmon polariton , surface plasmon , ohmic contact , optics , wavelength , dielectric , plasmon , tin , optoelectronics , refractive index , waveguide , surface roughness , nanotechnology , layer (electronics) , physics , metallurgy , composite material
Dielectric loaded surface plasmon waveguides (DLSPPWs) comprised of polymer ridges deposited on top of CMOS compatible metal thin films are investigated at telecom wavelengths. We perform a direct comparison of the properties of copper (Cu), aluminum (Al), titanium nitride (TiN) and gold (Au) based waveguides by implementing the same plasmonic waveguiding configuration for each metal. The DLSPPWs are characterized by leakage radiation microscopy and a fiber-to-fiber configuration mimicking the cut-back method. We introduce the ohmic loss rate (OLR) to analyze quantitatively the properties of the CMOS metal based DLSPPWs relative to the corresponding Au based waveguides. We show that the Cu, Al and TiN based waveguides feature extra ohmic loss compared to Au of 0.027 dB/μm, 0.18 dB/μm and 0.52 dB/μm at 1550nm respectively. The dielectric function of each metal extracted from ellipsometric spectroscopic measurements is used to model the properties of the DLSP-PWs. We find a fairly good agreement between experimental and modeled DLSPPWs properties except for Al featuring a large surface roughness. Finally, we conclude that TiN based waveguides sustaining intermediate effective index (in the range 1.05-1.25) plasmon modes propagate over very short distances restricting the the use of those modes in practical situations.