Soft-Colloids on Plasmonic Surfaces: Optothermal Trapping and Assembly
Abstract
The proposed objective was to study optothermal trapping, assembly and scattering from individual dielectric soft-matter based micro-colloidal architectures placed on a variety of plasmonic platforms. In this project, we utilized optical tweezers to study the optical interaction between an isolated colloid that harbors whispering gallery modes, and a plasmonic thin film which facilitates plasmons. We explored mirror-coupled microsphere and showed that it can narrow the angular distribution of photoluminescence from WS2 monolayers. I have summarized some new opportunities of performing optical trapping of plasmonic colloids with beams carrying orbital angular momentum of light. We published a couple of collaborative papers on interaction between two dimensional materials with substrates using dielectric engineering. The tools that we had developed to perform optothermal trapping has turned out be very versatile and useful for the characterization. Of importance to the project were the publications related to optothermal evolution of active colloids in a structured optical trap and simultaneous detection of spin and orbital angular momentum of light via coherent light scattering from a single plasmonic nanowire. These papers showed experimental aspect of utilizing soft colloidal platforms to trap and interrogate both structured light and soft matter. In a recent paper titled "Emergence of Directional Rotation in an Optothermally Activated Colloidal System" we demonstrate the experimental emergence of directional rotation in thermally active-passive colloidal structures under optical confinement. The observed handedness of the rotation can be controlled by changing the relative positions of the constituent colloids. The angular velocity of rotation is sensitive to the intensity of the incident optical fields and the size of the constituent colloidal entities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 11, 2023
- Accession Number
- AD1226691
Entities
People
- G. V. Kumar
Organizations
- Indian Institutes of Science Education and Research