Zhang, Y., O’Faolain, L., & Ramer, G. (2023). Design and Simulation of Bragg Grating Based Optomechanical Sensor for Atomic Force Microscopy. In Papers and Presentations from the COMSOL Conference 2023. Comsol Conference Munich 2023, Munich, Germany. Comsol multiphysics. https://doi.org/10.34726/5579
Silicon photonics has shown great potential in bringing together mechanical probes and optical cavity as compact sensors for many sensing applications. In this work, we present the integration of a waveguide Bragg grating (WBG) onto a cantilever beam, utilizing a Silicon-on-insulator (SOI) structure as an optomechanical sensor for atomic force microscopy (AFM). The flexibility of the COMSOL Multiphysics software enables us to model the mechanical characteristics of the cantilever and link the mechanical bending effects to the optical transmission simulations. Within these simulations, the nanoscale force applied to the cantilever tip results in cantilever beam deformation, represented by a picometer scale shift in optical resonance frequency. The simulation is carried out for the proposed Bragg grating design, featuring 80 gratings, and attains a force sensitivity approximately 16 m/N, corresponding to a cantilever stiffness 0.06 N/m.
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Research facilities:
Universitäre Service-Einrichtung für Transmissionselektronenmikroskopie
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Project title:
European Joint Doctorate Programme on Optical Sensing using Advanced Photo-Induced Effects: 860808 (European Commission)
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Additional information:
In this research paper, we designed and simulated a 3D Bragg grating-based optomechanical sensor using COMSOL Multiphysics software. This sensor is built upon a single-mode symmetric slab waveguide featuring planar Bragg gratings. It was designed with core dimensions in the sub-micron range, allowing for seamless integration into the evolving field of miniaturized photonic circuits.
To the best of our knowledge, this represents the first comprehensive 3D coupled finite element analysis aimed at understanding the mechanical stress-induced effects on electromagnetic wave simulations. This study serves as a crucial reference point for guiding the design and experimentation of optomechanical sensors.