Novel optical-waveguide sensing platform based on input grating coupler
Silicon oxynitride optical waveguides with a grating coupler were used for a label-free detection approach that measures the change of refractive index at the grating surface. Two approaches were used for the grating fabrication: (i) commercially available linear gratings were used as stamps for imprint lithography and the pattern was transferred by dry-etching; (ii) polystyrene microspheres self-assembly in an ordered close-packed array was exploited to obtain a two-dimensional grating with hexagonal symmetry. Optical coupling into slab waveguides of both visible (633nm) and tunable infrared (1550 nm) lasers was characterized as a function of incident angle in a custom-made automated apparatus. Sensitivity to different aqueous solutions was demonstrated with low loss waveguides fabricated using low-frequency plasma-enhanced chemical vapor deposition. The exploitation of the tunability of telecom infrared lasers and of the two-dimensional hexagonal grating coupler has the ultimate goal of providing a high performance, compact sensor that does not require mechanical moving parts.
Duke Scholars
Published In
DOI
ISSN
ISBN
Publication Date
Volume
Related Subject Headings
- 5102 Atomic, molecular and optical physics
- 4009 Electronics, sensors and digital hardware
- 4006 Communications engineering
Citation
Published In
DOI
ISSN
ISBN
Publication Date
Volume
Related Subject Headings
- 5102 Atomic, molecular and optical physics
- 4009 Electronics, sensors and digital hardware
- 4006 Communications engineering