Today, the dimensions of the smallest objects of a semiconductor circuit and the diameter of the dendrites of the human nerve cells are not only of the same order of magnitude but almost equal to 20 nm. The difference lies in the density of the structures. The distance between the objects of the semiconductor circuit can be down to 20 nm.

The distance between the dendrites is significantly greater. This makes it possible to make dendrites visible, even with a coarser resolution than 20 nm. This should be done using a 2-beam interference microscope.

The improvement of the signal-to-noise ratio is of great importance without affecting the object.  Simultaneous recording for the Structured Illumination signals is possible with sufficient signal to noise.

With conservative (Full Field) Structured Illumination and near UV, a point spread function in X, Y and Z of around 60 nm (FWHM) is expected. This value should be significantly reduced for Structured Illumination and laser scanning.

This is a good prerequisite for the measurement of small objects in the brain by signal height. This could make it possible to detect brain diseases earlier.

Microscope Set-up

Semiconductor Manufacturing 1988

Cr-Mask with lines from 0,2-1,0 μm width

Objective: 50x / 0,95

M. Lacombat et al., Solid State Technology/ August 1980

Light-lnduced Fluorescence,1992

Test Wafer with Structures in 360 nm Thick Resist
Lines Perpendicular and Parallel to Wollaston Split
N.A. =0,85,
λ =700 nm,
Magnification = 3 600 x
Lines and Dots nominal from 100 to 1 000 nm
Smallest Visible Line = 100nm, k =0,12
Smallest Hardly Visible Dot =200 nm, k = 0,24

Conclusion:
Phase Difference
» Rotation of the Polarization Plane Virtual Phase Shift
» Rotation of the Polarizer

Jae Sung Park, Experiments in Fluid 37 (2004) 105-119

Optical Signal Evaluation

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Don’t work, because of complete light pipes