Université de Fribourg

Numerical study of Anderson localization of terahertz waves in disordered waveguides

Lapointe, Clayton P. ; Zakharov, Pavel ; Enderli, F. ; Feurer, T. ; Skipetrov, S. E. ; Scheffold, Frank

In: EPL (Europhysics Letters), 2014, vol. 105, no. 3, p. 34002

We present a numerical study of electromagnetic wave transport in disordered quasi–one-dimensional waveguides at terahertz frequencies. Finite element method calculations of terahertz wave propagation within LiNbO3 waveguides with randomly arranged air-filled circular scatterers exhibit an onset of Anderson localization at experimentally accessible length scales. Results for the average...

Université de Fribourg

Noise in laser speckle correlation and imaging techniques

Skipetrov, S. E. ; Peuser, Joern ; Cerbino, Roberto ; Zakharov, Pavel ; Weber, Bruno ; Scheffold, Frank

In: Optics Express, 2010, vol. 18, no. 14, p. 14519-14534

We study the noise of the intensity variance and of the intensity correlation and structure functions measured in light scattering from a random medium in the case when these quantities are obtained by averaging over a finite number N of pixels of a digital camera. We show that the noise scales as 1/N in all cases and that it is sensitive to correlations of signals corresponding to adjacent...

Université de Fribourg

Photocount statistics in mesoscopic optics

Balog, Sandor ; Zakharov, Pavel ; Scheffold, Frank ; Skipetrov, S. E.

In: Physical Review Letters, 2006, vol. 97, p. 103901

We report the first observation of the impact of mesoscopic fluctuations on the photocount statistics of coherent light scattered in a random medium. A Poisson photocount distribution of the incident light widens and gains additional asymmetry upon transmission through a suspension of small dielectric spheres. The effect is only appreciable when the average number of photocounts becomes...