title: On-chip temperature compensation in an integrated slot-waveguide ring resonator refractive index sensor array.
abstract: We present an experimental study of an integrated slot-waveguide refractive index sensor array fabricated in silicon nitride on silica. We study the temperature dependence of the slot-waveguide ring resonator sensors and find that they show a low temperature dependence of -16.6 pm/K, while at the same time a large refractive index sensitivity of 240 nm per refractive index unit. Furthermore, by using on-chip temperature referencing, a differential temperature sensitivity of only 0.3 pm/K is obtained, without individual sensor calibration. This low value indicates good sensor-to-sensor repeatability, thus enabling use in highly parallel chemical assays. We demonstrate refractive index measurements during temperature drift and show a detection limit of 8.8 x 10-6 refractive index units in a 7 K temperature operating window, without external temperature control. Finally, we suggest the possibility of athermal slot-waveguide sensor design.
authors.affiliation: Microsystem Technology Laboratory, School of Electrical Engineering, KTH - Royal Institute of Technology, Osquldas väg 10, SE-100 44 Stockholm, Sweden. kristinn.gylfason@ee.kth.se
authors.forename: Kristinn B
authors.initials: KB
authors.lastname: Gylfason
authors.forename: Carl Fredrik
authors.initials: CF
authors.lastname: Carlborg
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kaźmierczak
authors.forename: Fabian
authors.initials: F
authors.lastname: Dortu
authors.forename: Hans
authors.initials: H
authors.lastname: Sohlström
authors.forename: Laurent
authors.initials: L
authors.lastname: Vivien
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Barrios
authors.forename: Wouter
authors.initials: W
authors.lastname: van der Wijngaart
authors.forename: Göran
authors.initials: G
authors.lastname: Stemme
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D012031:Refractometry / Q000295:instrumentation*; D018511:Systems Integration; D013696:Temperature; D014159:Transducers