e-Article
Silicon Nitride Photonic Particle Detector—Experiments and Model Assessment
Document Type
Periodical
Author
Source
IEEE Sensors Journal IEEE Sensors J. Sensors Journal, IEEE. 21(17):18829-18836 Sep, 2021
Subject
Language
ISSN
1530-437X
1558-1748
2379-9153
1558-1748
2379-9153
Abstract
Sensors based on the interaction between analytes and the evanescent field of a silicon nitride waveguide are emerging in the field of bio-medical and environmental applications. We designed and implemented the first single particle detector based on this sensor principle that consists of a silicon nitride waveguide with sub-micron dimensions. The detection capabilities of the prototype were demonstrated with polystyrene latex (PSL) spheres equal to or greater than Ø200 nm. Single PSL spheres caused a decrease of the transmission through the waveguide from 0.2 up to 10%, depending on their diameter and position with respect to the waveguide. The experiments were supported by 3D finite element method (FEM) simulations of the particle-waveguide interaction. The simulated relative scattered power of a single sphere is in agreement with experimental results obtained from two different setups. The silicon nitride photonic chip was fabricated with a plasma-enhanced chemical vapor deposition (PECVD) process, which is compatible with established complementary metal-oxide-semiconductor (CMOS) processes for high-volume production. The demonstrator setup was realized with an external laser and photodetector, but with recent advances in light source and detector integration, our work leverages the realization of a fully integrated, low-cost photonic particle detector.