High-sensitivity polymer-based bimodal plasmonic refractive index sensors with polymer cladding

Optics Express, vol. 33, pp. 9813

Abstract

Plasmonic refractive index sensors are essential for detecting subtle variations in the ambient environment through surface plasmon interactions. Current efforts utilizing CMOS-compatible, plasmo-photonic Mach-Zehnder interferometers with active power balancing exhibit high sensitivities at the cost of fabrication and measurement complexity. Alternatively, passive bimodal plasmonic interferometers based on SU-8 waveguides offer cost-effectiveness and a smaller device footprint. However, their waveguides are exposed to ambient conditions and currently lack the necessary opto-mechanical isolation. In this work, we introduce the new SX AR LWL 2.0 polymer cladding material, which provides a high refractive index contrast to the SU-8 core, while ensuring compatibility with SU-8 waveguides. Our sensors consist of an aluminum plasmonic stripe and a bilayer SU-8 photonic waveguide core which is cladded with the SX AR LWL 2.0 polymer. They achieve a sensitivity of (6108 ± 13) nm/RIU (refractive index unit), where the error indicates the data fitting tolerance, and a limit of detection of 1.6 × 10 −7 RIU, in aqueous solutions, surpassing both traditional and polymer-based bimodal plasmo-photonic sensors. This new cladding material paves the way for more efficient and integrated bimodal plasmonic refractive index sensing platforms for a wide range of applications.

Authors 14

1. Omkar Bhalerao
2. Stephan Suckow Aachen AMO GmbH

   AMO (Germany)

   Affiliation as printed

   AMO GmbH

3. H. Windgassen Aachen AMO GmbH

   AMO (Germany)

   Affiliation as printed

   AMO GmbH

4. Harry Biller
   Affiliation as printed

   Allresist GmbH, Am Biotop 14, Strausberg

5. Konstantinos Fotiadis
   Affiliation as printed

   CIRI-AUTH, Balkan Center

6. Stelios Simos
   Affiliation as printed

   CIRI-AUTH, Balkan Center

7. E. Chatzianagnostou

   Aristotle University of Thessaloniki

   Affiliation as printed

   CIRI-AUTH, Balkan Center

   Aristotle University of Thessaloniki (University Campus, 54124 Thessaloniki, Greece - Greece)

8. Dimosthenis Spasopoulos
   Affiliation as printed

   CIRI-AUTH, Balkan Center

9. Pratyusha Das

   Université Bourgogne Europe

   Affiliation as printed

   Université Bourgogne Europe

10. Laurent Markey

    Université de Bourgogne · Laboratoire Interdisciplinaire Carnot de Bourgogne · Université Bourgogne Europe

    Affiliation as printed

    Université Bourgogne Europe

    ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne (Université de Bourgogne - 9 avenue Alain Savary - BP 47870 - 21078 Dijon Cedex - France)

11. Jean‐Claude Weeber

    Université de Bourgogne · Laboratoire Interdisciplinaire Carnot de Bourgogne · Université Bourgogne Europe

    Affiliation as printed

    Université Bourgogne Europe

    ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne (Université de Bourgogne - 9 avenue Alain Savary - BP 47870 - 21078 Dijon Cedex - France)

12. Nikos Pleros

    Aristotle University of Thessaloniki

    Affiliation as printed

    CIRI-AUTH, Balkan Center

    Aristotle University of Thessaloniki (University Campus, 54124 Thessaloniki, Greece - Greece)

13. Matthias Schirmer
    Affiliation as printed

    Allresist GmbH, Am Biotop 14, Strausberg

14. Max C. Lemme Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen - RWTH Aachen University = Rheinisch-Westfälische Technische Hochschule Aachen (RWTH Aachen – Templergraben 55 – 52062 Aachen (Hausanschrift) – 52056 Aachen (Postanschrift) – Deutschland - Germany)