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Q: Fachverband Quantenoptik und Photonik
Q 57: Poster: Quantum Optics and Photonics III
Q 57.17: Poster
Donnerstag, 14. März 2019, 16:15–18:15, S Fobau Physik
Signal contributions in photothermal deflection spectroscopy for optical absorption measurements — •Walter Dickmann1,2, Johannes Dickmann2, Florian Bruns1, and Stefanie Kroker1,2 — 1LENA Laboratory for Emerging Nanometrologie, TU Braunschweig, Langer Kamp 6a/b, 38106 Braunschweig, Germany — 2Physikalisch-Technische Bundesanstalt Braunschweig, Bundesallee 100, 38116 Braunschweig, Germany
Since its development in 1980, collinear photothermal deflection spectroscopy (PDS) has been used for the spatial resolved determination of optical attenuation coefficients. We investigate the influence of several previously unconsidered contributions (e.g. thermal surface deformation) on the measurement signal in crystalline silicon and gallium arsenide by comparing numerical results with experimental data. The results show that angular effects can increase the surface absorption signal by more than two orders of magnitude, depending on the detector distance and probe beam collimation. That is an important result concerning recently discussed dominating surface absorption in highly pure silicon [1].
[1] Khalaidovski, A., Steinlechner, J., & Schnabel, R. (2013). Indication for dominating surface absorption in crystalline silicon test masses at 1550 nm. Classical and Quantum Gravity, 30(16), 165001.
This research is supported by the DFG within research training group Metrology for Complex Nanosystems (GrK 1952/1).