Thomas Ehrenreich is a senior physical scientist at RAND. Before coming to RAND, he served as a Defense Advanced Research Projects Agency (DARPA) program manager in the Microsystems Technology Office (MTO) from 2021 to 2025. At DARPA, he initiated and led the Modular Efficient Laser Technology (MELT) program, launched in 2021, which developed scalable and manufacturable high-power laser systems for defense applications. He also led the Atomic–Photonic Integration (A-PhI) program, which developed next-generation optical atomic clocks and matter-wave-based gyroscopes for precision navigation and sensing. In addition, he initiated and led a Special Access Program (SAP) in MTO and led another SAP in the Strategic Technology Office (STO).
Prior to DARPA, Ehrenreich held leadership roles at the Missile Defense Agency’s Sensor and Directed Energy Technology Office from 2016 to 2021, culminating in his role as advanced sensor product manager. In that capacity, he managed innovative programs in precision tracking, advanced detection systems, and high-energy laser scaling technologies.
Ehrenreich has coauthored 40 plus peer-reviewed publications and conference proceedings. He is internationally recognized for pioneering several firsts in the field of laser physics, including the demonstration of the world’s first diode-pumped alkali laser (DPAL), the first 1 kW thulium-doped fiber laser at 2 µm, and the first 3 kW beam-combinable fiber amplifier.
Ehrenreich's other research interests span from visible and X-ray spectroscopy, atomic lifetime measurements, ion-atom collisions, to the study of coherent elliptical Rydberg atoms. He holds a Ph.D. in physics from Kansas State University.
Education
Ph.D. in physics, Kansas State University; M.Sc. in physics, Aarhus University; B.Sc. in computer science, Aarhus University