Photonic Sensing and Flow Interaction Laboratory

Mission Statement

The Limbach research group at the University of Michigan is dedicated to advancing the science and application of lasers and optical technologies to address critical challenges in aerospace sensing, power delivery, and propulsion. We pursue fundamental and applied research at the intersection of photonics, plasma physics, gas dynamics, and aerospace systems, with the goal of developing transformative capabilities for next-generation flight and space systems.

Our research efforts focus on two complementary thrusts:

First, we develop and deploy state-of-the-art laser and optical diagnostics to advance our understanding of plasmadynamics and hypersonic flow physics. These tools enable precise, non-intrusive measurements under extreme thermophysical conditions, providing critical insights into phenomena that are otherwise difficult to probe.

Second, our group develops and explores transformational concepts for in-space power and propulsion, leveraging high-power lasers, atomic beams, and other concepts that enable the next generation of space mobility and energy infrastructure.

Through our research, we aim to redefine the boundaries of what’s possible as we shape the next era of aerospace innovation.

News and Events

Upcoming Events

AIAA Ascend/Aviation Conferences: Ivan Bao and Kaeshav Chandrasekar will be presenting their latest results.
GoSwift Lidar Project SRR at the University of Michigan: We are excited to host the GoSwift team for our SRR in July!
Plasma Summer School: We are excited for Megan Aardema to attend the APS Plasma Summer School in Minnesota!

News

Excited to be part of the SPAR project led by Prof. Jorns. This 5-year program focuses on developing versatile space propulsion and power architectures through support by the US Space Force. More information here.
Honored to receive a DARPA Young Faculty Award (YFA). This project focuses on new technology for long-range and over-the-horizon power beaming across the surface in support of future lunar activities.
Congratulations to Kaeshav Chandrasekar on being awarded the NASA Space Technology Graduate Research Opportunity (NSTGRO) fellowship!

Our laboratory is located on the second floor of the François-Xavier Bagnoud Aerospace Engineering Building on UM North Campus. During their research efforts, group members work collaboratively to solve problems and gain technical experience in laser physics, optics, spectroscopy, plasma physics, vacuum science and high-speed aerodynamics.

Paper Highlight

"Characterization of a Sensitive Inverted Pendulum Thrust Stand for Pulsed Propulsion with Optical Heterodyne Sensor and Lock-in Detection"

Abstract: In this paper, we present the design, characterization, and calibration of an inverted pendulum thrust stand designed for ultra-sensitive measurement of pulsed, periodic thrust. Target applications include photonic propulsion, breakthrough propulsion, and other low-thrust propulsion mechanisms that can be modulated. High sensitivity is achieved by implementing optical heterodyne measurement of displacement, which we show achieves sub-nm resolution. In addition, the high quality factor of the rotational resonance in the stand is exploited to amplify the displacement response to pulsed, resonant thrust generation by several orders of magnitude. As a demonstration of the stand’s high sensitivity, we perform a first calibration using light pressure generated by nine reflections of a continuous-wave laser producing an average power of up to 10 Watts. The calibration is performed at a resonant frequency of f = 0.748 ± 0.005 Hz and a quality factor of Q ∼ 85. Using a modulated square wave forcing with 50% duty cycle, we determine a sensitivity slope of 464 ± 20 nN/cycle and a detection limit of < 100 nN.

OPEN POSITIONS

Postdoctoral Openings: None at this time.

Graduate Research Assistants: We are always searching for motivated and technically excellent students to join our research group. Application information can be found on the AERO graduate admissions website here.

Undergraduate Research Assistants: Academically strong and motivated students are encouraged to inquire about directed study and research opportunities throughout the year. Please contact Dr. Limbach directly for more information at limbach@umich.edu.