Length Determination using Interferometry
Faculty Sponsor
Anthony Masiello, Eastern Washington University
Research Project Abstract
Determining the distance light must travel through a gas (the path length) is often difficult to determine, especially in multipass gas cells which have multiple reflections and curved mirror surfaces that are used to increase the path length in these devices. The goal of this research is to explore an alternate method to determine the optical path length of a multipass gas cell utilizing interferometry and the known index of refraction of a gas. Path length determination is accomplished by analyzing interference fringe patterns that result from changing the pressure in a gas cell that is on one arm of an interferometer. This results in interference fringes that are counted and related to the change in pressure, obtaining the path length of the cell. This method yields lower uncertainties in the measurement of the path length compared to physical measurement, leading to greater certainty in gaseous chemical concentrations.
Session Number
PS2
Location
Graves Gym
Abstract Number
PS2-w
Length Determination using Interferometry
Graves Gym
Determining the distance light must travel through a gas (the path length) is often difficult to determine, especially in multipass gas cells which have multiple reflections and curved mirror surfaces that are used to increase the path length in these devices. The goal of this research is to explore an alternate method to determine the optical path length of a multipass gas cell utilizing interferometry and the known index of refraction of a gas. Path length determination is accomplished by analyzing interference fringe patterns that result from changing the pressure in a gas cell that is on one arm of an interferometer. This results in interference fringes that are counted and related to the change in pressure, obtaining the path length of the cell. This method yields lower uncertainties in the measurement of the path length compared to physical measurement, leading to greater certainty in gaseous chemical concentrations.
