Phase Imaging in Plant Cells and Tissues - Biomedical Optical Phase Microscopy and Nanoscopy - page 53

to make predominantly a ring illuminator in the condenser and then introduce a ring in the
objective with a cavity or increased height introducing thus a phase delay or advances in the
objective to the light entering it and also causing the phase delayed light or accelerated light
wave to have a different absorption in this region. The theory is shown graphically in Figure 4.1 .
Images that are produced using such methodology are shown in Figure 4.2 . Note the halo
around each boundary. There is also a further anomaly in the image. The outer part of the
image has different contrast than the regions in the center and there is a further problem in
Phase plate
Phase chang e by
preparation
Unaltered phase
Preparation
Light source
Figure 4.1
Formation of phase contrast image.