Discipline: Biological Sciences
Subcategory: Climate Change
Luil Menberu - Delaware State University
Co-Author(s): Caio Azevedo- Delaware state University, Dover Delaware ; MH HIaing-Delaware state University, Dover Delaware ; Amir Khan -Delaware state University, Dover Delaware
Atmospheric oxygen (O2) and its isotopic ratios (16O18O) are important for understanding many with planetary, earth observation and geochemistry applications, especially in deciphering past climates. The ratio of isotopes from marine sediments, ice cores, or fossils is indicative of O2 in water and its changes with the climate. In this project we design and develop an optical system for detection of O2 at 760 nm. One of the methods for detection that is widely used is the Multipass Herriot cell, in conjunction with a tunable laser spectroscopy known for its high sensitivity and specificity. The Herriot cell consists of two spherical mirrors with an aperture in which the laser passes through and exits with the help of plane guiding mirrors for detection. The spherical mirrors have some properties that can be described mathematically using the Matrix Ray analysis. The optical systems can be written in a 2×2 matrix which describes the position and angle; In addition, the optical system can be characterized by ABCD matrix which acts on the input ray to produce the output ray. This matrix is known as the ray-transfer matrix. As a performance evaluation of the optical system we show higher detection sensitivity of atmospheric O2 by probing several rotational-vibrational molecular transitions of 16O2 and 16O18O atmospheric oxygen in the A-band region around a wavelength of 760 nm.
Funder Acknowledgement(s): We acknowledge the Optical Science Center for Applied Research (OSCAR), the financial support of the National Science Foundation (NSF-CREST grant # 1242067), the National Aeronautics and Space Administration (NASA MIRO grant # NNX15AP84A).
Faculty Advisor: Dr Mohammad A. Khan, firstname.lastname@example.org
Role: My part of this research was to study and understand what the oxygen isotope are, along with their use in identifying climate change. In addition, I designed the multiples Herriot cell with spherical mirrors to measure and analyze the concentration of oxygen using a laser that operates in the infrared region. I also worked on the path length of the system that results in different absorption of oxygen molecules. I utilized the lab view software to acquire the data and make further analysis.