Spectroscopy of Narrow-Band Light Sources using a Michelson Interferometer and an SLM

Lewis, Jesneil Lauren (2025) Spectroscopy of Narrow-Band Light Sources using a Michelson Interferometer and an SLM. Masters thesis, Indian Institute of Science Education and Research Kolkata.

Text (MS Dissertation of Jesneil Lauren Lewis (20MS113)) 20MS113_Thesis_file.pdf - Submitted Version Restricted to Repository staff only Download (15MB)

Abstract

The Michelson Interferometer is one of the classic setups in the field of interferometry and spectroscopy. This simple, yet elegant design has been used and modified to probe the smallest (eg. testing molecules in FTIR spectroscopy) up to the largest scales (eg. tracking the motion of high mass celestial bodies using gravitational waves). In this project we once again redesign a Michelson Interferometer by replacing one of the mirrors with a Spatial Light Modulator (SLM), in order to generate the spectrum of a source, using images of the resulting fringes, without recourse to any moving parts. The fundamental principle for a Michelson Interferometer is 2Δd = mλ, where Δd is the path difference between the two arms of the interferometer, m is order of each fringe, and λ is the wavelength of input light. The traditional understanding is that by changing Δd, we translate over the different orders of m, for a fixed λ. We flip this around and ask, on changing Δd, can we select out the different λs within the source by tracking each fringe (essentially keeping m fixed), thereby obtaining the spectrum of the source. Through the course of this thesis, I provide a practical demonstration of the above idea, and show that we can indeed perform spectroscopy using this method. In addition, I will cover many of the benefits, challenges, and limitations of using this technique over other conventional methods.

Actions (login required)

View Item