Principal Investigator

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Dr. Mitchell Spearrin is an Associate Professor of Mechanical and Aerospace Engineering at UCLA. Prof. Spearrin’s research focuses on spectroscopy and optical sensors, including laser absorption and fluorescence, with experimental application to advanced propulsion, energy systems, and other dynamic flow fields. His interests extend to fundamental chemical kinetics studies with relevance to pollutant formation and alternative fuels, as well as broader applications of spectroscopy that involve trace gas detection for environmental monitoring and biomedical devices. Dr. Spearrin completed his Ph.D. at Stanford University, working in the High Temperature Gas Dynamics Laboratory. Prior to his academic career, Dr. Spearrin worked for Pratt & Whitney Rocketdyne as a combustion devices development engineer.

PI Message: Research in our laboratory is primarily experimental, and involves elements of fluid mechanics, thermodynamics, heat transfer, chemistry, mechanical design, and applied optics. Projects typically involve a combination of fundamental spectroscopy, measurement science, and engineering in the context of thermo-fluid systems. Please see the research links above to learn more.

Lab Employment Openings! We are currently looking to fill the following positions: PhD-seeking Graduate Student Research Assistant, Postdoctoral Researcher, Masters-seeking Graduate Student Research Assistant, and Undergraduate Student Research Assistant. Please see more detail regarding these openings in the 'Join Us' link.

Research Elements

Fundamental collisional and radiative processes determine the intensity and structure of observed spectra for a given atom or molecule and are dependent on thermodynamic conditions. In our laboratory, we investigate these basic mechanisms using laser spectroscopy in optical gas cells and high-temperature furnaces, providing insight into physical behavior at the molecular level at conditions relevant to sensing applications of interest. Fundamental spectroscopic constants can be determined experimentally and integrated into spectral models or more comprehensive databases.

Rapid advances in photonics equipment provide for constant opportunities to expand experimental capabilities using laser spectroscopy. Increasing power, efficiency, tunability range, tuning speed, and wavelength coverage of lasers can provide for new methods. In our lab, we investigate significant extensions of existing techniques and entirely new methods that involve increasing temporal, spatial, and spectral dimensions/resolution by way of absorption and fluorescence interactions.

Engineering Applications

Laser spectroscopy is particularly well-suited to sensing applications that require high time-resolution (or fast response time) and non-intrusive detection. These technical requirements are typical of reacting flow fields where the time scales of chemistry are very short (microsecond to millisecond) and where intrusive probes can alter the parameters of interest. High-speed flows, with steep spatial and temporal flow-field gradients, have analogous diagnostic needs. More diverse applications of our sensing methods are unified by the need for quantitative, time-sensitive information required to understand complex, dynamic systems that typically involve competing flow-field mechanisms.