| PhD Viva

Name of the Speaker: Mr. Nirjhar Kumar (EE15D208)
Guide: Dr. Ananth Krishnan
Online meeting link: https://meet.google.com/ehi-rmnw-dqs
Date/Time: 17th October 2024 (Thursday), 3:00 PM
Title: Opto-Electrochemical detection using Composite Optical Vortex Beams

Abstract :

We present two methods to extract faradaic current in electrochemical (EC) reactions: i) an EC method and ii) an on-chip optical method. The EC method uses a triangular waveform along with sine and cosine modulated triangular waveforms, followed by post-processing of the three obtained current waveforms to separate faradaic and nonfaradaic components in an EC reaction. The optical method employs a proposed hybrid fork grating that generates composite optical vortex (COV) beams upon optical illumination while simultaneously serving as an electrode for the EC reaction. The EC reaction of 10 mM potassium ferricyanide induces a refractive index change of approximately 1e-4, leading to a 40-degree rotation of the COV beam. This rotation correlates with faradaic current density and bulk RI change, unaffected by nonfaradaic components. Beneficial for low current scenarios, this method enables signal amplification, advancing EC research across various fields.