Mapping the Optomechanical Coupling Mediated by Light among Mechanical Resonators Including Multilayer Cavity and Molecules

Abstract

For a wide range of health applications, label-free sensing is essential, and microphotonics offers innovative technical solutions for pursuing important objectives. It has been shown that the strong light/matter coupling formed between a cavity and molecules through light excitation enhances biological and clinical applications by providing deep insights into molecular analysis. The multilayer cavity’s proposed architecture is meant to promote a robust interaction between light and matter. The top layer was made of silver Ag multishape features that, after being synthesized and characterized, were immobilized on the surface of a multilayer system. A layer of indium tin oxide (ITO) was flipped to produce two distinct layouts. An investigation of the mode behavior was conducted to describe the two layouts; experimental and numerical results point to a strong light/matter interaction by the ITO/SiO2/spacer/Ag design. For the characterization of light/matter coupling, a fluorophore was adsorbed on the surface; the anticrossing energy was then examined by integrating the experimental data with a three mechanical oscillator model. To show the system’s sensitivity, the analysis was carried out again using bovine serum albumin (BSA). The protein is water-soluble and exhibits an infrared absorption band (amide I), while also being active in the Raman region. In addition, it may consistently bind to Ag multishape features. The excellent sensitivity was demonstrated, enabling the use of image analysis to capture the surface-enhanced Raman scattering of BSA. In conclusion, the suggested sensing approach raises fresh possibilities for highly sensitive biomolecule detection method and encourages results when used as a fundamental sensing technique to investigate molecular patterns.