Fabrication of Biosensor Chips - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 121

shown in Fig. 6.8. Due to the lexibility in the pattern design of
the optical mask, gray-scale lithography can be adopted for the
fabrication of diffraction gratings with complex geometries, such as
two-dimensional, Fresnel, or blazed gratings.
Figure 6.8 Fabrication processes of gray-scale lithography.
In 2003 Mouroulis et al. [21] adopted this method to produce
blazed grating with grove spacing in the order of tens of microns.
Figure 6.9 shows the planar Fresnel lens fabricated with gray-scale
lithography on a silicon substrate [22]. The planar Fresnel lens
consisted of 10 proiled gratings for X-ray diffraction, where each
grating has a uniquely deined proile.
Figure 6.9 Planar Fresnel lens consisting of 10 proiled gratings for X-ray
diffraction [22]. Each grating has a uniquely deined proile.
The diameter of the lens is 1.6 mm.