Precision Laser Diagnostics for Energy and the Environment
Prof. Greg Rieker
Department of Mechanical Engineering
2009: PhD, Stanford University
2004: MS, Stanford University
2002: BS, 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.
Senior Research Associates
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 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.
Marta Ruiz-Llata is a Professor in the Department of Electronic Technology at the University Carlos III of Madrid (UC3M, Spain) since 2010, where she also received the degree of “Ingeniería Industrial” in 1998 and the PhD degree in Electrical, Electronics and Automation Engineering in 2005. She joined the Precision Laser Diagnostics group at CU in September 2019 for one year during her sabbatical leave from UC3M.
Her research projects have been involved with the development of optical sensors for industrial and environmental applications and the investigation of machine learning algorithms with application in instrumentation systems. She has experience on interferometry, infrared and mid-infrared absorption spectroscopy, photoacoustic spectroscopy, and LiDAR systems. At CU her research focus on analysing measured spectral data of combustion and environmental processes acquired with optical frequency comb systems, with emphasis on the identification of large molecules characterized by complex and spread spectral signatures.
Marta has found in Boulder and at CU a very friendly city and very friendly people, so she hopes there are many opportunities to continue collaborating in the future.
CIRES Research Scientist
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.
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 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 Strongearned 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. In 2019 Liz received an NSF award to support her graduate studies at CU Boulder. Recently Liz has been engaged in reporting and presenting her research as follows:
May 2020 a talk rpresented virtually at CLEO 2020
May 2020 2nd author on a poster presented virtually at CLEO 2020
and, May 2020 2nd author on a paper published in Optics Letters called ''Detection technique effect on rotational Doppler measurements''
Liz loves being outside, especially when that involves rock climbing, skiing, or running!
Alex Rybchuk earned his B.E. 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 third-year PhD student in the Mechanical Engineering department, Alex is using computational fluid dynamics to model the transport and dispersion of trace gases in the lower atmosphere, with the ultimate goal of improving methane monitoring systems for natural gas infrastructure. When he’s not on campus, you can find him slacklining or climbing in Boulder Canyon.
Emily Hannah earned her B.A. in Engineering Sciences from Dartmouth College in Hanover, New Hampshire, in 2016. While at Dartmouth she was an NCAA Division I cross-country skier. After graduation, she moved west to Bozeman, Montana where she worked building LIDAR lasers at Bridger Photonics and as the assistant coach for Montana State University’s cross-country ski team. Originally from Steamboat Springs, she returned to Colorado in the 2018 to begin her PhD work in Electrical Engineering. Emily’s research is focused on developing experiments to measure the effects of turbulent air on the propagation of frequency combs and other lasers. When not doing optics, Emily loves trail running, skiing, and reading Kurt Vonnegut.
David Yun earned his B.S. in Mechanical Engineering and B.M. in Piano Performance at the University of Maryland College Park (UMCP). During his time there he researched pressure and temperature optical fiber sensors, which led into engineering for a sensor startup after graduation. Afterwards, he came back to UMCP to research spatial performance in cochlear implant users. Now at CU Boulder, pursuing a PhD in Mechanical Engineering, he is excited to set the sights of dual-frequency combs on hot methane. In his spare time, he loves playing on his humble piano keyboard and getting lost in grocery stores.
Charlie Callahan earned his B.S. in Mechanical engineering and minor in physics from CU Boulder. During his time there he worked at a diffraction grating manufacturing company and designed a laser based flame sensor for his B.S. Senior Design Project. This led him to be a co-inventor on a patent. Charlie learned that he liked Boulder and engineering so he decided to stay at CU to pursue his PhD in Mechanical Engineering. During his (minimal) free time, Charlie like to ride mountain bikes, ski and snowboard.
Scott received his bachelors and masters in mechanical engineering at Brigham Young University in Provo, Utah. He has spent two summers at Lockheed Martin aeronautics as an F-35 design engineer and another summer at Sandia in Livermore studying methane and hydrogen leaks using Raman scattering. His masters research focused on temperature measurements for gas turbine engines using infrared emission from the water vapor in the pressurized post-combustion gases. Scott started his PhD work with the Precision Laser Diagnostics Lab in the fall of 2019 and will focus on taking frequency comb laser measurements in scram jet engines. When he’s not in the lab, he loves hiking and generally being outside, especially in the mountains. He's excited to soak in as many of the 300 days of Boulder sunshine as he can.
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.
Mechanical Engineering Interns
Christopher Kling is currently pursuing a BS in Mechanical Engineering at CU. He is interested in mechanical design and studying fluid dynamics. He is working with Amanda Makowiecki to design and fabricate a wind tunnel to study the spread of wildfires. He is working on the flow characteristics of the tunnel. In his free time he enjoys skiing, hiking, and riding motorcycles.
Cory Childs is pursuing his B.S in Mechanical Engineering at the University of Colorado Boulder. He worked as an intern in the research and development department of a small renewable wood pellet company called Lignetics, Inc. in the Spring of 2019. He is assisting in the fabrication of a wind tunnel which will provide experimental validation for computational models of wildfire spread. When not studying or working he enjoys playing basketball, guitar and exploring boulder with buds.
Cameron Casby earned his B.S. in mechanical engineering and a minor in computer science from CU Boulder in May 2019. He is currently pursuing a M.S. in mechanical engineering from CU with an emphasis in design. Since September 2018, Cameron has worked with Ryan Cole on the high pressure cell in the Precision Laser Diagnostics Laboratory. His work has included the development of an auto-alignment routine to minimize the effects of beam steering and the design and implementation of a graphical user-interface for the purpose of centralizing monitors and managing pressure controls. In his free time, Cameron enjoys playing club soccer for CU, offroading in his Jeep Wrangler, and snowboarding.
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. Amanda is received her PhD in Mechanical Engineering at the University of Colorado Boulder in December 2019. Her research utilizes wavelength modulation spectroscopy (WMS) to quantify combustion product concentrations and temperatures in thruster plumes. Amanda began working at NOAA in Boulder in January 2020. 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.
Anthony Torres graduated with his B.S./M.S. in Aerospace Engineering Sciences at the University of Colorado Boulder in December 2018. He has a strong passion for rocket propulsion and space exploration, and hopes to advance humankind's presence in the solar system and beyond. He worked on dual frequency spectroscopy for dynamic high pressure systems during his time at the Precision Laser Diagnostics Laboratory. His thesis is available online. In his free time he enjoys various electronics projects, hiking, camping, and building high-powered rockets. He his currently an Aerospace Engineer in the Advanced Development Programs group at Blue Origin.
Torrey Hayden earned her PhD in Mechanical Engineering from CU-Boulder in 2018 studying innovative techniques for measuring process reactions in industry applications using laser absorption spectroscopy. She is now a Spectroscopy Scientist Engineer at Zolo Technologies Inc. in Golden, CO.
Jason Christopher earned his PhD in Mechanical Engineering from CU-Boulder in 2018 studying Bayesian statistical techniques to combine laser diagnostics with fluid dynamic simulations. He is now an operational test director in the Air Force for space systems.
Paul Schroeder earned his PhD in Mechanical Engineering from CU-Boulder in 2017 studying laser diagnostics in harsh environments. Paul completed an NRC postdoc at NOAA in Boulder, CO and is now with General Atomics.
Bennett Sodergren earned his MS in Mechanical Engineering from CU-Boulder in 2016. He is now with Vescent Photonics, Golden, CO.
Alan Sanchez received his MS in Aerospace Engineering Sciences at the University of Colorado Boulder in 2018. He completed his BS in the same program in May 2017. Alan is currently working at Tesla.