Biomedical Engineering Reference
In-Depth Information
Shielded Vertical
Transfer Register
Transfer Gate
IC
Sense Node
and Amplifier
Serial Readout
Photo
Diodes
Figure 6.2-7 The interline transfer in a CCD.
surrounded by a cylindrical shell of glass of lower re-
fractive index, called the cladding. Optical fibers may be
classified in terms of the refractive index profile of the
core and whether one mode (single-mode fiber) or many
modes (multimode fiber) are propagating in the guide
(
Figure 6.2-9
). If the core, which is typically made of
high-silica-content glass or a multicomponent glass, has
a uniform refractive index
n
1
, it is called a
step-index
fiber. If the core has a nonuniform refractive index that
gradually decreases from the center toward the core-
cladding interface, the fiber is called a
graded-index
fiber. The cladding surrounding the core has a uniform
Shielded Vertical
Transfer Register
Pixel
1
1
Shielded Vertical
Transfer Register
Pixel
2
2
3
3
4
4
5
5
Active Detectors
Active Detectors
Figure 6.2-8 Detailed layout of the 2:1 interlaced array: (a) the odd field is clocked into the vertical transfer register and (b) the even
field is transferred.
