. Significance : Optical coherence tomography (OCT) is an interferometric imaging modality, which provides tomographic information on the microscopic scale. Furthermore, OCT signal analysis facilitates quantification of tissue optical properties (e.g., the attenuation coefficient), which provides information regarding the structure and organization of tissue. However, a rigorous and standardized measure of the precision of the OCT-derived optical properties, to date, is missing. Aim : We present a robust theoretical framework, which provides the Cramér –Rao lower bound for the precision of OCT-derived optical attenuation coefficients. Approach : Using a maximum likelihood approach and Fisher information, we derive an analytical solution for when the position and depth of focus are known. We validate this solution, using simulated OCT signals, for which attenuation coefficients are extracted using a least-squares fitting procedure. Results : Our analytical solution is in perfect agreement with simulated data without shot noise. When shot noise is present, we show that the analytical solution still holds for signal-to-noise ratios (SNRs) in the fitting window being above 20 dB. For other cases ( , focus position not precisely known), we show that the numerical calculation of the precision agrees with the derived from simulated signals. Conclusions : Our analytical solution provides a fast, rigorous, and easy-to-use measure for OCT-derived attenuation coefficients for signals above 20 dB. The effect of uncertainties in the focal point position on the precision in the attenuation coefficient, the second assumption underlying our analytical solution, is also investigated by numerical calculation of the lower bounds. This method can be straightforwardly extended to uncertainty in other system parameters.

J. (2022). Strange metal electrodynamics across the phase diagram of Bi 2-x Pb x Sr 2-y La y CuO 6+δ cuprates. Physical Review B, 106(5), [054515].

We present optical measurements of the transition metal dichalcogenide PdTe2. The reflectivity displays an unusual temperature and energy dependence in the far-infrared, which we show can only be explained by a collapse of the scattering rate at low temperature, resulting from the vicinity of a van Hove singularity near the Fermi energy. An analysis of the optical conductivity suggests that below 150 K a reduction in the available phase space for scattering takes place, resulting in longlived quasiparticle excitations. We suggest that this reduction in phase space provides experimental evidence for a van Hove singularity close to the Fermi level. Our data furthermore indicates a very weak electron-phonon coupling. Combined this suggests that the superconducting transition temperature is set by the density of states associated with the van Hove singularity.

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