Unwrapping a full temporal cycle in time domain thermoreflectance for enhanced measurement sensitivity in thermally insulating materials.

Autor: Donovan BF; Department of Physics, United States Naval Academy, Annapolis, Maryland 21402, USA., Gray TL; Department of Physics, United States Naval Academy, Annapolis, Maryland 21402, USA., Wilson AA; U.S. Army Research Laboratory, Adelphi, Maryland 20783, USA., Warzoha RJ; Department of Mechanical Engineering, United States Naval Academy, Annapolis, Maryland 21402, USA.
Jazyk: angličtina
Zdroj: The Review of scientific instruments [Rev Sci Instrum] 2022 Aug 01; Vol. 93 (8), pp. 084904.
DOI: 10.1063/5.0089075
Abstrakt: Time delayed pump-probe measurement techniques, such as Time Domain Thermoreflectance (TDTR), have opened up a wealth of opportunities for metrology at ultra-fast timescales and nanometer length scales. For nanoscale thermal transport measurements, typical thermal lifetimes used to measure thermal conductivity and thermal boundary conductance span from sub-picosecond to ∼6 nanoseconds. In this work, we demonstrate a simple rearrangement and validation of a configuration that allows access to the entire 12.5 ns time delay available in the standard pulse train. By reconfiguring a traditional TDTR system so that the pump and probe arrive concurrently when the delay stage reaches its midpoint, followed by unwrapping the temporal scan, we obtain a dataset that is bounded only by the oscillator repetition rate. Sensitivity analysis along with conducted measurements shows that great increases in measurement sensitivity are available with this approach, particularly for thin films with low thermal conductivities.
Databáze: MEDLINE