Nano-Holographic Interferometry for In-Vivo Observations - Biomedical Optical Phase Microscopy and Nanoscopy - page 346

Figure 17.4 shows the diffraction pattern recorded by the sensor. Besides the diffraction
pattern of the polystyrene microsphere, the image recorded by the optical microscope also
contains a system of rectilinear fringes. All the FT observations were made in the central
region (i.e., limited by the first dark ring) of the pattern that has a radius of 1.05 m.

Figure 17.4 also shows the FT of the recorded image. By filtering this FT, different families
of fringes were extracted. Recalling the complex argument of the diffraction evanescent
orders presented in Section 17.2 , Figure 17.4 also shows the values of complex sine for the
different evanescent diffraction orders which are up to 120. It is also possible to see that the
diffraction rectilinear fringes are modulated by the diffraction pattern of the particle; an
inset in Figure 17.4 shows the cross-section of these fringes in the region corresponding to
the central crown of the diffraction pattern of the sphere. In this cross-section, it is possible
to see the modulation of a system of parallel fringes produced by the presence of the
polystyrene sphere.

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17.4 System of Fringes Contained in the Recorded Image:
Multi-k Vector Fields

Aside from the diffraction pattern of the polystyrene microsphere, the image recorded by
the optical microscope also contains a system of rectilinear fringes. Understanding the

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3.8 3.9 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6 6.1 6.2

Microns

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Figure 17.4
System of fringes observed in the image of the 6 m diameter polystyrene microsphere. The dotted

circle represents the first dark ring in the particle diffraction pattern [10] .

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