People

Research Group Fall 2024

Left to Right: Reganne Watts, Alejandro Roa Quintero, Ashley Carman, Thomas Garrett, Prof Chris Limbach, Kaeshav Chandresekar, Rishav Choudhary, Ivan Bao. Not Present: Bilal Hassan

Chris Limbach

Assistant Professor

Department of Aerospace Engineering

University of Michigan

FXB Office 3021

limbach@umich.edu

Professor Limbach is director of the Photonic Sensing and Flow Interaction Laboratory at the University of Michigan. He obtained B.S. degrees in Engineering Physics and Astronomy from the University of Arizona in 2009 and a Ph.D. in Mechanical and Aerospace Engineering at Princeton in 2015. Before joining UM, Prof. Limbach was an assistant professor at Texas A&M University from 2018 - 2022 where he led the Laser Diagnostics and Plasma Devices Laboratory. At UM his research focuses in two areas equally. One is the development of non-intrusive optical and laser-based measurement techniques for high-speed flows, plasmas and remote sensing with applications to turbulent hypersonic flows and high temperature non-equilibrium environments relevant to aerodynamics, propulsion, and plasma science. He is particularly interested in multi-dimensional imaging, fast modulation methods for interrogation and detection, development of pump-probe techniques, and leveraging recent advances in photonic and opto-electronic devices. The second focus is on transformational beam propulsion techniques for space power and propulsion. This area includes laser ablation, enhancement cavities, in-situ resource utilization and investigating the mutual interaction of co-propagating laser and atomic beams.

Megan Aardema

Megan Aardema is a postdoctoral research fellow in Professor Christopher Limbach’s lab. She received her B. S. in Chemistry from Calvin College, where she did research with Dr. Douglas Vander Griend, studying the self-assembly process of a large supramolecular structure with spectrophotometric titrations. Megan received her Ph.D. in Chemistry from Texas A&M University, under the advisement of Dr. Simon North. Her dissertation was on the UV photodissociation of ozone, using velocity map imaging and REMPI to probe the molecular fragments and study the wavelength dependence of the fragment energy distributions. Megan was a postdoctoral research associate in Dr. Timothy Minton’s group at the University of Colorado, where she worked on designing an instrument to simulate space conditions for materials testing. Megan is interested in the spectroscopy of small molecules and is working on developing LIF diagnostics for the characterization of electric propulsion systems.

Kaeshav Chandresekar

Kaeshav Chandrasekar is a second-year Aerospace Engineering PhD student and NSTGRO Fellow under Professor Christopher Limbach at the University of Michigan, Ann Arbor. He received his B.S. in Electrical Engineering from the University of California, Los Angeles (UCLA) in 2023, while being an undergraduate research assistant at the Plasma Energy and Space Propulsion Laboratory under Professor Richard Wirz. Some of his undergraduate work included systems engineering and architecture, power electronics, miniature ion thrusters, and electrospray thruster research. Currently, he is working on a self-guiding laser and particle beam for over-the-horizon lunar power transfer and deep space propulsion. He is passionate about furthering humanity's understanding of space through both robotic and human exploration. In his spare time, Kaeshav enjoys playing the violin, tennis, and weightlifting.

Bilal Hassan

Bilal Hassan is a second-year Aerospace Engineering PhD student advised by Prof. Christopher Limbach at the University of Michigan, Ann Arbor. Bilal received his Bachelor of Science Degree in Aerospace Engineering with a Minor in Physics at the University of Florida in December 2022. While at UF, Bilal was the Project Manager of the Swamp Launch Spaceport America 22' Rocketry Team, and an undergraduate research assistant at the Applied Physics Research Group under the direction of Prof. Subrata Roy. In the summer of 2022, he assisted in the development of Incoherent Thomson Scattering laser diagnostic at Georgia Institute of Technology's High Power Electric Propulsion Laboratory for use in Hall Effect Thrusters. Bilal is primarily interested in the use of laser diagnostics to investigate plasma turbulence and electron dynamics within Electric Propulsion Devices and similar magnetized low-temperature plasmas.

Anya Jewell

Anya Jewell is a first-year Aerospace Engineering PhD student under Professor Christopher Limbach at the University of Michigan. She obtained her Bachelor of Science in Physics from Rensselaer Polytechnic Institute in 2023. During her time at RPI, she completed a Student Undergraduate Laboratory Internship (SULI) at Lawrence Berkeley National Laboratory (LBNL), where she assisted in commissioning a new beamline for the laser plasma acceleration of ions and first discovered her interest in lasers and optical systems. She spent the following summer at the National Radio Astronomy Observatory (NRAO), researching masers and star-formation in the Andromeda Galaxy. Anya’s interests lie at the intersection of physics and engineering, and specifically in the advancement of humanity’s understanding of astronomy and astrophysics via the development of novel diagnostics and instrumentation. In her free time, Anya enjoys reading, writing, hiking, and playing soccer.

Ivan Bao

Ivan Bao recenly completed his Masters degree in AE and UM and is a first year PhD student in under Professor Christopher Limbach. His research at PSFIL focuses on exploring laser-induced lasing in gas using femtosecond pulse pairs, with the potential to develop a diagnostic technique. He is also studying the enhancement of laser-induced air breakdown using consecutive laser pulses, with possible applications in remote acoustic wave generation and flow control.

Nikolay Tokmantsev

Nikolay Tokmantsev is a first-year PhD student in Aerospace Engineering advised by Professor Christopher Limbach. His research focuses on the interaction of laser beams with shockwaves in confined geometries, combining numerical simulation and optical diagnostics. Nikolay received his Bachelor's degree from Polytechnique Montréal (Canada) with a specialization in fluid dynamics, followed by a Master’s degree from ISAE-Supaéro (France) with a specialization in spacecraft structures and materials. While at Polytechnique Montréal, he was team lead for both the Attitude Determination and Control System (ADCS) of the Canadian Space Agency–affiliated SEDS-Canada Stratospheric Balloon Experiment and the CubeSat team. At Supaéro, he also served as team lead for the National Centre for Space Studies (CNES)–affiliated Students in Microgravity Zero-G experiment. In his free time, he enjoys scuba diving, piloting, skydiving, and boxing.

Nicholas Donatelli

Nicholas Donatelli is finishing his Aerospace Engineering Master's student at the University of Michigan, Ann Arbor. Nicholas recieved his Bachelor of Science Degree in Engineering Physics at the Embry-Riddle Aeronautical University in 2023. While at Embry-Riddle, Nicholas designed and built a Hall thruster as well as a free-space optical communication device. Nicholas' current research at PSFIL revolves around developing a three-photon absorption laser induced fluorescence diagnostic technique for atomic hydrogen and atomic oxygen in plasma. Additionally, Nicholas is working on a coherent microwave scattering system for radar REMPI measurements of relative electron density in plasma. Outside the lab, Nicholas enjoys playing polo, scuba diving, or travelling.

Ashley E Carman

Ashley E Carman is a senior pursuing her Bachelors of Science in Aerospace Engineering at the University of Michigan, with a minor in physics, and a focus on sustainable propulsion. She is an employed student researcher of the PSFIL lab, working to integrate general space systems with other project definitions for laser-specific applications. Currently she is leading the Thrust Test Stand team working to characterize laser ablation on ISRU-candidate materials as a form of propulsion. She was also President of M-SAAVE (Michigan Sustainability Applications for Aerospace Vehicle Engineering), a humanitarian aerospace club on campus, and External Vice President of WAA (Women in Aeronautics and Astronautics). In her free time she sings with the UMS Choral Union, and enjoys the outdoors. In her previous professional experience, she has interned with SpaceX and Blue Origin, as well as managed the MBSE lab on campus. Her interests lie in in-space propulsion methods and their applications to advancing human presence in space.

Reganne Watts

Reganne Watts is an undergraduate student at the University of Michigan majoring in Aerospace Engineering with the International Minor for Engineers. At PSFIL, her research focuses on the in-situ resource utilization of lunar simulants for laser ablation propulsion. She previously interned at the Georgia Tech Research Institute working on a novel spacecraft navigation platform. On campus, she is on the fencing club‘s Women‘s Epee Team and is actively involved in Women in Aeronautics and Astronautics. She enjoys spending her free time reading, traveling, and visiting museums.

Thomas Garrett

Thomas Garrett is an undergraduate student majoring in Aerospace Engineering with an interest area in systems engineering and bioastronautics. He is a member of the Thrust Test Stand research team, investigating the ablative effects of lasers on lunar simulants as a form of ISRU propulsion. Thomas is also a member of MASA, Michigan’s student rocketry team, as well as the Outreach Chair for Michigan’s student branch of the American Institute of Aeronautics and Astronautics. Additionally, he marches as a part of the Michigan Marching Band, where he plays the trombone. In his free time, he enjoys hiking, biking, and coding.

Jeremy Plimpton

Jeremy Plimpton is a third-year undergraduate pursuing his Bachelor of Science in Physics at the University of Michigan. He works as an undergraduate student research assistant in the PSFIL lab, where he contributes to the assembly and characterization of a glow discharge plasma reactor for water vapor plasmas. He also has developed a photon counting system using Single-Photon Avalanche Diodes for low-light laser diagnostics and propulsion applications. Most recently, Jeremy’s work has involved designing a dual-purpose collection system accommodating both TALIF and PGR.

Robert Randolph

Visiting Student from Texas A&M University Aerospace Engineering

Robert Randolph received his Bachelors degree in Mechanical Engineering from Rutgers University in 2019 and his Masters of Science degree in Aerospace Engineering from Texas A&M in 2021 while working with the Optical Probing and Manipulation group. In 2022 he received the NASA FINNEST-AO award to explore optical hole burning in rubidium vapor for high precision wind measurements for remote sensing.

Former Students and Alumni

Research Group Circa Spring 2021 at Texas A&M

Boris Leonov

Dr. Boris Leonov received his Bachelors degree in Aeronautics and Astronautics from Purdue University in 2018. Since joining the lab, Boris has worked on a laser diagnostic system based on laser-induced breakdown spectroscopy (LIBS) for heavily dust-laden flows. During his time with the group, Boris worked on advanced laser diagnostic approaches based on injection-seeding of an optical parametric oscillator (OPO), with applications to plasma propulsion and hypersonic ground test and evaluation.

Madison Hetlage

NSTGRO Fellow

Dr. Madison (Maddie) Hetlage received her Bachelors degree in Aerospace Engineering from Notre Dame and was the recipient of the Sigma Gamma Tau National Undergraduate Award in 2018. During her time with the group, Maddie investigated a new technique for rapid atmospheric profiling of humidity, temperature, and velocity using LIght Detection And Ranging (Lidar). The new approach is based on an optically pumped barium vapor filter for filtering of Rayleigh backscattered light. Through a combination of experiment and modeling, this technique is being developed for future applications to airborne supersonic LIDAR, air-data and ground test. In 2020, Maddie received the NASA Space Technology Graduate Research Opportunities Fellowship and is currently working on her postdoctoral research at NASA Langley Research Center.

Weixiao Wang

MS Student

Weixiao Wang received his bachelor’s degree in Mechanical Engineering and Mathematics from University of California, Irvine. He completed his master's degree in Aerospace Engineering at University of Michigan, Ann Arbor in 2024. During his time in the Photonic Sensing and Flow Interaction Laboratory under Professor Limbach’s supervision, he worked working on Femtosecond Laser Diagnostics. Currently, he is pursuing his PhD at Princeton University.

Clark Pehrson

Clark received his MS degree with the research group on the topic of FLEET velocimetry in hypersonic flow, in particular for boundary layer profiling. He is currently working at Sandia National Laboratory.

Rishav Choudhary

Dr. Rishav Choudhary received his bachelor’s degree in aerospace engineering from the Indian Institute of Technology (IIT), Kanpur in 2016. Following this, he obtained his master’s and Ph.D. from Stanford University in 2018 and 2023 respectively. His doctoral work was on the development of a physics-based, computationally inexpensive framework for modeling chemical kinetic models for jet fuels, and their sustainable alternatives. The work leveraged experiments performed on shock tubes using laser absorption spectroscopy. While at PSFIL, Rishav worked on the development of a heterodyne interferometry-based diagnostic for probing turbulent compressible and reacting flows. His research interests lie in the development and application of advanced optical diagnostics for fluid flows and plasmas.

Yue Wu

Dr. Yue Wu received his doctoral degree at the University of Tennessee Knoxville (UTK) in 2015, with his thesis focusing on development of radar detected resonant enhanced multi-photon ionization (REMPI) diagnostic for methyl radical, ethylene and molecular oxygen. After spending two years as a postdoctoral researcher at UTK following his doctorate, Yue arrived at Texas A&M University in early fall 2017. Dr. Wu has pursued detailed studies of laser-generated plasmas for diagnostic and flow control applications, especially breakdown and hydrodynamics under low pressure conditions. His research has also involved optical diagnostics and aero-optical properties of non-equilibrium gases generated by nanosecond discharges. He is now employed at a research scientist at MetroLaser Inc. in Laguna Hills, CA.

Atulya Kumar

Atulya Kumar received his Bachelors of Technology (B Tech) in Mechanical Engineering from the Amrita School of Technology Science in 2016. After graduation, he served as a project engineer at the Laboratory for Hypersonics and Shock Wave Research at the Indian Institute of Science working on gas dynamics of combustion driven shock tubes. Having arrived at Texas A&M in June 2019, Atulya studied the interaction of laser-generated plasmas with small particles and droplets with applications to diagnostics, remote sensing, combustion ignition, mixing and flame-holding. For this work, Atulya has constructed and operated an electrodynamic balance (EDB), allowing electrical levitation of single metal and dielectric particles and droplets of water and hydrocarbon fuels. High speed microscopy, spectroscopy and advanced laser diagnostics are applied towards quantitative understanding of the multi-phase interaction with high spatiotemporal resolution. He is continuing his education as a PhD student at the University of Luxembourg.

Frisco Koelling

Frisco joined the Limbach research group in summer 2018. As an undergraduate research assistant, he researched laser-generated plasmas using a diagnostic known as two-color interferometry and developed a powerful least-squares method for analysis of phase map data for extraction of plasma parameters. He has also demonstrated plasma measurements near the surface of a liquid droplet. After completing his bachelor’s degree at Texas A&M in spring 2020, Frisco continued his tenure in the lab as a master’s student. During his master’s degree, Frisco worked on burst mode filtered Rayleigh measurements inside the NAL’s new hypervelocity expansion tunnel (HXT). He is now employed at Lockheed Martin.

Grant Erickson

Grant joined the lab as an undergraduate researcher in the summer of 2020, and, after graduating with his bachelor’s degree in Aerospace engineering from Texas A&M in December 2020, he became a full time member as a master’s student. During his tenure with our group, Grant has been working on the Ballistic, Aero-optics, and Materials (Mini BAM) facility located in the ALLEMO facility. As an undergraduate, he developed a software package to calculate laser wavefront distortions via a Shack-Hartman sensor installed in the facility, as well as developed a computer simulation of the laser propagation through Mini BAM. As a graduate student, Grant has led the empirical testing within this facility with the hopes of validating newly developed laser and turbulence interaction models. Also as an undergraduate, prior to joining our group, Grant worked at the Advanced Vertical Flight Lab at Texas A&M developing novel MAV’s! Grant is currently employed as a controls research engineer at Lockheed Martin’s Advanced Technology Center.

Hayden Morgan

Hayden received his Bachelors of Science degree in Mechanical Engineering from University of Cincinnati in 2019. In 2020, he received the NASA Space Technology Graduate Research Opportunities Fellowship. During his graduate work, Hayden worked on design and commissioning of an ultra-high vacuum facility for studying optical interactions between co-propagating laser-cooled particle beams and laser beams. The objective of this work is the development of a self-guided beamed propulsion concept for high-velocity missions to the outer planets and even the nearest star systems. After graduation in Dec 2021, Hayden joined the team at ABL space systems as a hardware development engineer.

NASA Project Description: https://www.nasa.gov/directorates/spacetech/niac/2019_Phase_I_Phase_II/Self_Guided_Beamed_Propulsion/

Rohan Jillapalli

Rohan joined the lab in the spring of 2020 as an undergraduate researcher where he contributed heavily to the self-guided beamed propulsion concept. In addition to assisting Hayden with the experimental characterization of the rubidium jet source, Rohan also modeled the spatial and frequency dependence of the ionization of a rubidium atom beam through multiphoton ionization of two counter-propogating lasers as it pertains to an accelerating scientific spacecraft and a near earth beam transmitter. This latter work was implemented into a undergraduate thesis. During his time as a graduate student, Rohan has developed and worked toward the characterization of a supersonic rubidium source for this project.

Jacob Dewey

MS Student

Jacob graduated with a master’s degree at the University of Michigan, Ann Arbor in 2023. He received his B.S. in aerospace engineering from Auburn University in May 2022. Some of his undergraduate work included aircraft design and simulation tools, computational aerodynamics, and boundary layers. In PSFIL, investigated using plasma and lasers in high speed flow for potential application on supersonic/hypersonic vehicles. Currently, Jacob is a GNC engineer at BlueHalo.

Tyler Linfesty

Tyler Linfesty received his bachelor’s degree in Aerospace Engineering from the University of Michigan, Ann Arbor in May of 2023. Currently, he is enrolled in the Sequential Undergraduate/Graduate Studies program pursuing his Masters Degree in Aerospace Engineering. In the PSFIL he researched the dynamics of laser-guided electric discharges in supersonic flow for applications in the control hypersonic vehicles.

Alejandro Roa Quintero

Alejandro Roa Quintero received his bachelor’s degree from CentraleSupélec in France, where he worked under supervision of Professor Christophe Laux. His research at PSFIL focused on the development of a heterodyne interferometry-based diagnostic for reacting flows. His research interests are on hypersonics and high enthalpy flows, especially those applied to atmospheric reentry.