Greg Rieker
Prof. Greg Rieker
Assistant Professor
Department of Mechanical Engineering
ECME 226

2009PhD Stanford University
2004MS Stanford University
2002BS University of Missouri - Rolla

Prof. Rieker has been at CU since fall 2013. His teaching interests are in design and thermosciences. Prior to the University of Colorado, Greg spent a year as an NRC research associate at the National Institute of Standards and Technology (NIST), exploring the use of frequency comb lasers for sensing in practical systems. Prior to NIST, Greg developed and studied a plasma-based particle accelerator for medical applications, first as a postdoc at Stanford and then through a company that he co-founded. During his PhD, he developed laser-based sensors for a variety of combustion applications, including internal combustion engines, scramjet engines, and oil refinery process flames.

Prof. Rieker has a particular interest in mentoring and developing students into multi-faceted engineers – that is, engineers who are not only excellent researchers, but leaders and entrepreneurs with an eye toward creating opportunity for themselves and others.

Post-doctoral Research Associate

Sean Coburn Sean Coburn earned his BS in Chemistry and BA in Biology at Newman University in 2007. He then went on to earn a PhD in Chemistry from the University of Colorado Boulder in 2014 under the advisement of Prof. Rainer Volkamer. During his graduate work, Sean’s research revolved around field measurements of atmospheric trace gases using absorption spectroscopy. Additionally, his projects contained a focus on instrument development. This included the building and deployment of a ground-based passive remote sensor for the detection of halogen oxides and oxygenated volatile organic compounds in the coastal marine boundary layer; and an active in-situ sensor for the measurements of volatile organic compounds over the remote tropical Pacific Ocean. In his spare time, Sean likes spending time with his family in the mountains or enjoying other outdoor activities.
Nazanin Hoghooghi Nazanin Hoghooghi received her PhD in Optics from the College of Optics and Photonics (CREOL) at the University of Central Florida. During her PhD in Prof. Peter Delfyett's group, she developed a high-speed linear intensity modulator based on an injection-locked semiconductor laser for analog optical networks. After her PhD, she joined Prof. Ming Wu's group at the University of California-Berkeley, where she developed a low noise millimeter wave source using photonic techniques. She received a Marie Curie fellowship from the European Commission in 2013 and joined the Quantum Sensors Technologies and Applications (QTEA) network. She conducted her research at TOPTICA Photonics in Munich, Germany. She developed two Hz-linewidth cavity stabilized laser systems with relative short term stability of 10^-15 at 1 sec, and an optical link with phase noise cancellation to deliver the light from the Hz-level reference lasers to a home-built difference frequency generation (DFG) frequency comb. This enabled the first in depth characterization of a DFG frequency comb. Nazanin moved to Boulder with her husband in summer 2015. She joined the Precision Laser Diagnostics group in January, where she is working on highly sensitive frequency comb systems for the detection of hazardous trace gases.

CIRES Research Scientist

Caroline Alden Caroline Alden is a research scientist at CIRES. She is working with Greg Rieker at CU, and Colm Sweeney at the NOAA/ESRL Carbon Cycle Group to detect leaks of methane and other hydrocarbons during natural gas production and distribution, through inverse modeling of trace gases observed by open path frequency comb lasers. Prior to CIRES, Caroline was a postdoctoral fellow at Stanford University, working with Prof. Noah Diffenbaugh on connecting climate extremes in the Amazon Basin to variations in net biosphere exchange of CO2 with the atmosphere. Caroline earned a Ph.D. in Geology from the University of Colorado, Boulder in 2013, with Prof. Jim White and Dr. John B. Miller (NOAA/ERSL), for her work developing an inversion framework for 13C of atmospheric CO2, and exploring its potential as a tracer for regional drought stress in North America. She has also published work on global CO2 sink strength and on atmospheric 13CO2 as a potential indicator of global terrestrial carbon exchange, water stress, and partitioning C3/C4 plant productivity. Caroline’s love of exploring the outdoors led her to pursue arctic field geology at Colorado College, which led to an interest in climate change research and, eventually, the pursuit of techniques for interpreting the signals and signs left by nature and humans in atmospheric greenhouse gases.

PhD Students

Torrey Hayden Torrey Hayden is currently pursuing her Ph.D. in Mechanical Engineering at the University of Colorado, Boulder. A born and raised Coloradoan, it was a very easy choice to come back to Colorado after receiving her B.S. in Physics and Mathematics from St. Lawrence University in Canton, NY in 2013. In college, she volunteered with SLU Buddies, mentoring elementary and middle school students at local schools. Furthermore, she enjoyed mentoring other students in math and physics through tutoring and Quantitative Resource Center. Currently, her research includes developing a sensitive technique for measuring pollutants in the atmosphere and measuring reactions in industry applications using innovative techniques in laser absorption spectroscopy. In her free time, Torrey enjoys playing in the mountains, primarily skiing and hiking, and singing in a local gospel choir.
Amanda Makowiecki Amanda Makowiecki earned her B.S. in Mechanical Engineering from the University of New Hampshire where she applied experimental fluid dynamics to large scale wind turbine array designs and flow separation in shear wake flows. Amanda interned with BAE Systems for three years, where she worked on modeling and optimization studies for various military aircraft platforms. Currently Amanda is pursuing her PhD in Mechanical Engineering at the University of Colorado Boulder. Her current research utilizes wavelength modulation spectroscopy (WMS) to quantify combustion product concentrations and temperatures in thruster plumes. When not in the office Amanda can often be found in the mountains skiing, hiking or running, she also enjoys volunteering at the local humane society.
Jason Christopher Jason Christopher earned a B.S. in mechanical engineering from the United States Air Force Academy in 2007. While at the Academy, he interned at the Los Alamos National Laboratory researching deflagration properties of explosive materials. After the Academy, Jason earned an M.S. in mechanical engineering from Rice University with his thesis research focused on computational modeling of fluid-structure interactions of NASA parachutes; his research was advised by Dr. Tayfun Tezduyar. Upon graduation, he moved to Vandenberg Air Force Base, California where he worked as a range modernization and sustainment engineer acquiring telemetry systems to support space launch. Most recently, Jason completed an assignment as an Assistant Professor of Mechanical Engineering on the faculty of the United States Air Force Academy teaching statics and mechanics of materials, thermodynamics, and fluid mechanics. Currently Jason is pursuing his PhD in Mechanical Engineering and is co-advised by Drs. Greg Rieker and Peter Hamlington. His research focuses on combining experimental data obtained through laser spectroscopy with fluid dynamics computations. Outside of the office Jason enjoys hiking, biking and, his favorite, spending time with his wife, Shannon, and sons, Noah and Rowan.
Nate Malarich Nate Malarich earned his B.S. in Engineering Science in 2015. Born and raised in central Pennsylvania, Nate left the Penn State Nittany Lions for the true land of the mountain lions. The appeal of the laser frequency comb lured his research life away from ultrasound in solids to infrared in gases. Nate enjoys tinkering on the experiment table, and his PhD work has him tinkering with matrices as well. In his spare time, he enjoys riding and fixing cheap bicycles, playing ultimate with psychologists and aerospace engineers, and playing jazz piano with the rhythmically-inclined.
Ryan Cole Ryan Cole earned his B.A. in Physics and Mathematical Sciences at Colby College in Waterville, Maine. As an undergrad, he completed a senior thesis in ultra-cold plasma physics and spent a summer researching novel x-ray polarimetry detectors at NASA Goddard Space Flight Center. After graduation, he spent a year as an astrophysical research intern at the Gemini Observatory in Hilo, Hawaii. Ryan began his Ph.D. work in the Precision Laser Diagnostics Lab in the Fall of 2016. His research is focused on dual-frequency comb absorption spectroscopy of gasses at high temperatures and pressures. When not in the lab, he enjoys fly fishing, road biking, and hiking in the mountains around Boulder.
Elizabeth Strong Elizabeth Strong earned her S.B. in engineering sciences from Harvard College. At Harvard, Liz was an NCAA Div. 1 alpine ski racer, and she did research with Profs. Katia Bertoldi, Michael Brenner, and Joanna Aizenberg. After graduating from college in 2015, Liz went on to MIT where she worked in the lab of Prof. Pedro Reis. Liz completed her SM in mechanical engineering at MIT at the end of the summer of 2017. Liz is looking forward to living in Colorado again after a 6-year hiatus in Cambridge, MA. Liz loves being outside, especially when that involves rock climbing, skiing, or running!
Dan Petrykowski Dan Petrykowski is a Doctoral student in the Mechanical Engineering department at the University of Colorado Boulder. Previously, he worked in industry as an Applications Engineer, creating and implementing machining processes for high volume production manufacturing environments. Dan holds a Bachelor’s Degree in Mechanical Engineering from the University of Dayton and his current research focuses on the detection of reactive oxygen and hydrogen species in industrial film treating processes. When not working, you can find him playing any instrument he can acquire, or planning his next camping trip.
Alex Rybchuk Alex Rybchuk earned his BE in Mechanical Engineering at Cooper Union in New York City, specializing in thermofluid sciences. While there he worked at ConEdison, creating algorithms to detect and preempt corrosion-induced failure of transformers across the city. As a first-year PhD student in the Mechanical Engineering department, Alex is using computational methods to understand how methane travels in the lower atmosphere near natural gas facilities, ultimately aiming to improve its detection through experimental means. When he’s not on campus, you can find him slacklining, climbing, or rocking out on his guitar.

MS Students

Anthony Torres Anthony Torres is currently working toward an MS in Aerospace Engineering Sciences at the University of Colorado Boulder. After high school he attended Red Rocks Community College for two years gaining experience and completing the necessary general requirements of an engineering degree. Recently he interned with United Launch Alliance supporting the Atlas V Booster production, and worked with Colorado Space Grant Consortium to program image analysis and calibration scripts for the HELIOS V payload. He has a strong passion for rocket propulsion and hopes to pursue a PhD in the field with the goal of helping to develop a next generation rocket engine. He is working with Paul Schroeder and David Pfotenhauer on dual frequency spectroscopy for combustion environments. In his free time he enjoys various electronics projects and building high-powered rockets with the Colorado Boulder Rocketry Association.
Alan Sanchez Alan Sanchez is currently working towards his MS in Aerospace Engineering Sciences at the University of Colorado Boulder. He completed his BS in the same program in May 2017 and is now in the fifth year of the concurrent BS/MS program. His current research is towards the development of a laser-based control system intended to command and/or stabilize the burn temperature and reactive species concentration in the combustion gases of a burner and film roller system. In his free time, Alan enjoys breakdancing, volunteering for the CU Boulder chapter of the Society of Hispanic Professional Engineers, and traveling.

Lab Engineers

Robbie Wright Robbie Wright earned his B.S. in optical engineering in 2014 and his M.S. in optics in 2015, both from the Institute of Optics at the University of Rochester. He joined the Rieker group to help apply frequency comb lasers to the task of greenhouse gas detection. Robbie gained experience designing and using custom laser systems during his internships at L-3 Communications EOTech, the UR's Laboratory for Laser Energetics, and in the Kapteyn-Murnane group at CU. He is proud of his senior design project, a stereoscopic museum exhibit created for the Rochester Museum and Science Center. While not spending time in the dark trying to see the light, Robbie loves to ski, hike and run and also enjoys photography and film.
Griffith Wendland Griffith Wendland Earned his B.S. in Mechanical Engineering in 2017 at the University of Colorado, Boulder. During his undergraduate career he worked at MicroMotion designing and manufacturing test equipment for high precision flow meters and Ball Aerospace designing space craft mechanisms and assembly equipment. As Lab engineer he is supporting the mechanical design and manufacture of the next generation of equipment for GHG detection. Outside of Engineering, Griffith spends his time writing and performing poetry, climbing, running, and learning anything and everything that interests him.

Embedded Systems Engineer

Cesar Galan Cesar Galan Earned his B.S in Aerospace Engineering Science in 2017 at the University of Colorado, Boulder. In his time at CU Boulder, he completed research under Professor Sedat Biringen optimizing RANS models for turbulent channel flow, and working on a code to passively reduce turbulence on a flat plate using direct numerical simulations. As a lab engineer in Professor Rieker’s Lab, he has completed half dozen projects developing python classes in-house to control commercial hardware. Which allows the research group to use various devices through the existing python-base architecture. In his free time, he enjoys playing guitar and cello, going on climbing and backpacking adventures with his friends, and working on projects to make his life easier.

Mechanical Engineering Intern

Sonya Schuppan Sonya Schuppan is currently working toward a B.S. in Electrical and Computer Engineering at the University of Colorado Boulder. She is interested in embedded systems engineering and the integration of biomimicry into engineering designs. Sonya is working with Amanda Makowiecki to quantify and analyze properties of wood pyrolysis. In her free time, Sonya enjoys hiking, backcountry skiing, running, and playing cello in the CU Campus Orchestra.


Paul Schroeder Paul Schroeder earned his PhD in Mechanical Engineering from CU-Boulder in 2017 studying laser diagnostics in harsh environments. He is now an NRC postdoc at NOAA in Boulder, CO.
Bennett Sodergren earned his MS in Mechanical Engineering from CU-Boulder in 2016. He is now with Vescent Photonics, Golden, CO.