Universitiy of Potsdam

Applied Condensed Matter Physics

Prof. Dr. Reimund Gerhard
2016-11-04 16:30 by Manuel Schulze

From pyroelectric current to depth profile

With the thermal wave method we can create a strong temperature oscillation near the surface, but no localized strong oscillation at an arbitrary depth in the sample (this follows from the heat conduction equation). In mathematical terms, the measured current is a convolution of the pyroelectric coefficient p(x) with the temperature distribution:

where I~ is the pyroelectric current and D the thermal diffusivity. Unfortunately, solving for p(x) is an ill-conditioned problem. Various methods exist for retrieving p(x):

  1. Approximation method
  2. Regularization methods
  3. Fourier filtering

See the following page for some examples.