Presentation
4 March 2019 Rationally designed nanoantennas coupled to microtoroids for enhanced biochemical sensing (Conference Presentation)
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Abstract
Subwavelength systems such as optical nanoantennas are widely used for optical sensing due to their ultrahigh field localization. Compared to isolated nanoantennas, hybrid sensor systems composed of optical nanocavities and microcavities enjoy higher quality factor (Q) plasmonic-cavity modes, as well as larger resonance shifts for any given sensing target. We have shown that rational engineering of the coupling between nanoantennas can maximize the system’s sensitivity. This can be achieved through near-field optimization of the system to maximize the field enhancement and suppression of the far-field radiation to maintain the highest possible Q. Finite element eigenvalue analysis shows that a trimer plasmonic nanoantenna coupled to a whispering gallery mode (WGM) of a microtoroid cavity supports higher Q and field enhancement than single nanorods that are randomly scattered on the surface of microcavity. We have studied the robustness of this system against any possible perturbation in geometry of trimers such as length, angle or gap between the nanoantennas. On the basis of this study, a general design approach is introduced, which helps engineers to enhance the efficacy of plasmonic-photonics based biosensors.
Conference Presentation
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Cheng Li, Lei Chen, Euan McLeod, and Judith Su "Rationally designed nanoantennas coupled to microtoroids for enhanced biochemical sensing (Conference Presentation)", Proc. SPIE 10891, Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XVI, 108910I (4 March 2019); https://doi.org/10.1117/12.2509243
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KEYWORDS
Nanoantennas

Biosensing

Near field optics

Optical microcavities

Nanorods

Near field

Optical sensing

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