Alfredo Dubra's PhD thesis - Imperial College London

5. Preliminary experiments
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Figure 5.4: Reconstructed topography of two simulated small bubbles, of around 0.13
and 0.26 mm in diameter, with heights (depths) of 11 and 22 nm respectively. The axis
units are millimeters and the units on the color scale are nanometers. The error in
the peak-to-valley value in each of the reconstructed topographies versus the original
simulated phase is 15 % and 10 % respectively.
the µPhase2, and it was found that the values differ by around 6%.
5.4 Small detail test
When developing the software the question of whether any small detail could be seen
in the final tear topography arose, because of the non-linear filtering in the Fourier
domain and the smoothing that occurs in the unwrapping and integration processes.
Therefore, some interferograms that would result from a flat tear topography and a
series of bubbles with increasing size were simulated. Figure 5.4 shows the reconstructed
topography of two small bubbles, of around 0.13 and 0.26 mm in diameter,
with heights (depths) of 11 and 22 nm respectively. The errors in the peak-to-valley
in each of the reconstructed topographies with respect to the original simulated topography
are 15% and 10% respectively, suggesting that the presence of small details
can in principle be detected.
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