OPHIR BeamSquared, User Manual

Page: 97 / 112

Beam Alignment and Setup for Manual Mode 9.3.2
Avoid eye or skin exposure to direct or scattered radiation!
Before allowing laser energy to contact the camera sensor, it is important to limit the beam intensity.
Excessive laser energy will damage the camera.
The Pyrocam imager can be damaged at energy levels above 20 mJ/cm
2
(1ns pulse) or at power levels greater
than 4 W/cm
2
. Adjust these input limits downward based on the focused spot size. Beam splitters and/or filters
may be used to attenuate the beam, but care must be taken to prevent the introduction of distortions.
During an M
2
measurement operation, the peak
energy density that reaches the camera changes,
potentially over several orders of magnitude. This
is a result of the camera effectively moving from
a large unfocused spot near the lens, into and
through the focus at the waist, and then out
again to an unfocused spot. It is the user’s
responsibility to ensure the correct amount of
attenuation is used in order to prevent damage
to the camera.
Use ND filters near the laser head to attenuate the beam to a safe level. Additional ND filters can also be
added in front of the camera to further adjust beam brightness.
If camera or other configuration parameters need to be changed, do so now or restore the required
configuration. This will not be necessary if the last configuration saved corresponds to the current setup.
The following steps describe how to setup the rail with the lens and the camera:
1. Click Live Playback from the Run ribbon. The live video mode is provided to assist with
the alignment process. Live video will appear in the 2D Beam Display window.
2. The laser must be directed along an axis parallel to the rail, centered on the lens, and
centered on the camera. The beam must stay centered on the camera as the camera is
translated.
3. The X and Y axes of the camera must also be aligned with the X and
Y axes of the laser beam to collect meaningful beam propagation
results. To obtain proper alignment, it may be necessary to rotate
either the camera or the laser.
4. After making this adjustment, recheck the pointing accuracy by
translating the camera along the rail and confirming that the beam
remains centered in the beam window.
5. When the camera can travel the full length of the rail and the beam stays centered on the detector,
alignment is complete.