title: Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing.
abstract: In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved.
authors.affiliation: Department of Electrical and Information Engineering, Politecnico di Bari, Via E. Orabona 4, 70125 Bari, Italy. benedetto.troia@poliba.it.
authors.forename: Benedetto
authors.initials: B
authors.lastname: Troia
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK. a.z.khokhar@soton.ac.uk.
authors.forename: Ali Z
authors.initials: AZ
authors.lastname: Khokhar
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK. m.nedeljkovic@soton.ac.uk.
authors.forename: Milos
authors.initials: M
authors.lastname: Nedeljkovic
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK. s.reynolds@soton.ac.uk.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Reynolds
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK. y.hu@soton.ac.uk.
authors.forename: Youfang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK. g.mashanovich@soton.ac.uk.
authors.forename: Goran Z
authors.initials: GZ
authors.lastname: Mashanovich
authors.affiliation: Department of Electrical and Information Engineering, Politecnico di Bari, Via E. Orabona 4, 70125 Bari, Italy. vittorio.passaro@poliba.it.
authors.forename: Vittorio M N
authors.initials: VM
authors.lastname: Passaro
keywords: Vernier effect; integrated waveguide sensors; optical sensing; silicon