Measurements of thermally induced strains with micron-scale lateral spatial resolution, picosecond time resolution, and sub-picometer vertical sensitivity are achieved using a newly developed experimental method, time-domain probe beam defection (TD-PBD). TD-PBD is a pump-probe optical technique that combines an ultrafast laser oscillator as the light source, high frequency (10MHz) modulation of the pump beam, and a wide range of time delays (0-4ns) between the pump and probe. Deflections of the probe beam are measured by a position sensitive detector and an rf lockin amplifier. The beam-deflection data are analyzed using a detailed model of heat transport and thermally generated stresses and strains. Comparisons between the model and the data enable quantitative measurements of the coefficient of thermal expansion with a spatial resolution of 4m.
- Coefficient of thermal expansion
- Combinatorial materials science
- Pump-probe techniques
- Ultrafast laser metrology
ASJC Scopus subject areas
- Condensed Matter Physics
- Materials Science(all)