New Focus 8783 GuideStar, Руководство пользователя

Страница: 17 / 39

12
4.2
System set up
The Quick Start Guide contains information to set up the system. Please refer to
the quick start guide to install software, configure the cameras, and connect
components with the included cables. Additional details on hardware set up and
software operation are found below.
4.3 Hardware set up
4.3.1 Beam Pick-offs and Optical Power
The power required for the cameras is low, so it is recommend that the leakage
through HR mirrors with polished backsides be used as beam “pickoffs.” Other
options include reflections off AR surfaces or uncoated beam-splitters in the
beam. The saturation power of the cameras is shown in Figure 3.2a. If beam size
and exposure time are accounted for, this figure can be used to choose appropriate
pick-offs and attenuation for the beam. Fine tuning of power is accomplished via
the exposure time so as to maximize dynamic range.
Figure 9. Approximate saturation power of the cameras with a 10-ms
exposure time and a 2-mm beam diameter. Exposure time can range from 1 to
980 ms.
4.3.2
Optical Layout
The physical layout of the two cameras and two motorized mirror mounts may
affect the performance of the GuideStar II System. As a general guideline, the
separation between the mirrors and the separation between the cameras should be
large and comparable, while the separation between Mirror 2 and Camera 1
should be much shorter, as short as conveniently possible (see Figure 3.2b).
300 400 500 600 700 800 900 1000 1100 1200 1300
Wavelength (nm)
1 W
1 mW
1
m
W
1 nW