The characterization facility has been upgraded by designing and realizing a three axes
translator that mount on top a reflective objective and that is housed in a black box.
Figure 1.29 shows the black box and a detail of the reflective objective can be seen
on the middle part.
The translator is able to move the reflective objective in the x (150 mm) and y (30 mm)
directions as well as in the z direction to allow the beam focusing.
The reflective objective is illuminated through a 25 or a 10 pin-hole by a
fiber optic that in turn pick up the light from one of the two cameras of the
characterization system where usually are mounted the calibrated or tested detector.
This configuration allow us to have at the focal plane of the reflective objective a monochromatic spot with a size smaller than 10 FWHM. This is very useful to simulate a point-like source that can illuminate just a single pixel of a detector array.
Thus we can carry-out quantum efficiency measurements on single or sub-pixel taking into account for fabrication non-uniformity defects.