Ultra-sensitive refractive index sensor using CMOS plasmonic transducers on silicon photonic interferometric platform.
Opt Express
; 28(14): 20992-21001, 2020 Jul 06.
Article
in En
| MEDLINE
| ID: mdl-32680148
ABSTRACT
Optical refractive-index sensors exploiting selective co-integration of plasmonics with silicon photonics has emerged as an attractive technology for biosensing applications that can unleash unprecedented performance breakthroughs that reaps the benefits of both technologies. However, towards this direction, a major challenge remains their integration using exclusively CMOS-compatible materials. In this context, herein, we demonstrate, for the first time to our knowledge, a CMOS-compatible plasmo-photonic Mach-Zehnder-interferometer (MZI) based on aluminum and Si3N4 waveguides, exhibiting record-high bulk sensitivity of 4764â
nm/RIU with clear potential to scale up the bulk sensitivity values by properly engineering the design parameters of the MZI. The proposed sensor is composed of Si3N4 waveguides butt-coupled with an aluminum stripe in one branch to realize the sensing transducer. The reference arm is built by Si3N4 waveguides, incorporating a thermo-optic phase shifter followed by an MZI-based variable optical attenuation stage to maximize extinction ratio up to 38â
dB, hence optimizing the overall sensing performance. The proposed sensor exhibits the highest bulk sensitivity among all plasmo-photonic counterparts, while complying with CMOS manufacturing standards, enabling volume manufacturing.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Diagnostic_studies
Language:
En
Journal:
Opt Express
Year:
2020
Document type:
Article