Ch. 20. Safety Precautions Sec. 20.2. Light Source Safety
Optics Cover
Laser Module
Objective Lens
Hot Mirror
Figure 20.3.: Simplified laser path. Removing the optics cover exposes the hot mirror and laser module.
The non-visible laser light originates in the laser module and comes out as a collimated beam. The colli-
mated beam is reflected off of the hot mirror and into the objective lens, which focuses it onto the cantilever.
During normal operation the only place a person can be exposed to the light is where the light exits the
objective.
• While unlikely, it is possible to place a small mirror below the objective and reflect the light in the
direction of the user. Even then the beam spreads rapidly and is not powerful enough to classify
the instrument differently. Nevertheless, you should be aware of the fact that non-visible light is
coming out of the objective.
• While it is not recommended, it is possible to unscrew the objective lens by overcoming the loc
tite glue used to keep the lens in place. At this point a flat mirror placed under the beam exit can
reflect approximately 1 mW of collimated IR light into your eye. Never remove the objective lens
or you may void your warranty.
• Never change or remove the laser module without first turning off the laser power key on the
ARC2 controller. Never look directly into a plugged in laser module (
Figure 20.4 on page 233).
20.2.2.1. Laser Safety Interlocks
The laser on the Cypher AFM is turned on an off by a control voltage which originates inside the ARC2
controller. On its way to the laser the voltage passes through various safety switches. This electrical
path is explained in
Figure 20.5 on page 234 and in the following text.
BETA
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