Interference Nanolithography for Raman Signal Enhancement
presented by Matthew Donaldson C'20
Wednesday, April 17, 7:30 - 8:30pm, Woods Labs 216
Regular Raman spectroscopy measures vibrational and rotational energies, which helps identify and characterize the chemical composition of a sample. A limitation of this technique is that Raman signals are ordinarily weak. My project uses laser interference lithography to enhance that signal. Interference lithography can generate large-area patterns of ordered arrays of nanostructures, which in the case of silver can boost weak Raman signals. This enhancement is due to the excitation of surface plasmons in the silver nanostructures.
In my project, I experimented with the exposure time, array period and film thickness to fabricate silver nanostructures and test their performance as Raman enhancement substrates. Along with experimentally determining the optimal geometric parameters, I used the finite-difference time-domain numerical method to simulate the electric fields around the nanostructures that enable the enhancement of the Raman-scattered light.
Matthew Donaldson, C’20, is a junior physics major at the University of the South from New Canaan, Connecticut. He is a member of the Sigma Alpha Epsilon fraternity and has previously served on its executive board. Matthew is also a member of the club squash team and was inducted into Sigma Pi Sigma, the National Physics Honor Society. He will be attending engineering school next fall.