Iradion Infinity 1625, Руководство оператора

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21
Beam Expanders and Other First Optical
Surfaces
Caution
The optical intensity at the output window is
VERY high (>8500W/cm
2
). Any
contamination to the window surface could cause runaway destruction. To protect the
window, Iradion provides a power supply unit that includes a long life air pump and
filters to bathe the window in clean filtered air. Do NOT burn materials close to the
laser. The flow of air may not be enough to overcome the explosive vaporization of
objects near the output aperture.
The beam leaving the 1625 laser is very small and extremely intense. Optics positioned
in the beam must be of the highest quality to survive without damage. The first lens of a
typical system is most often a beam expander entrance optic.
Iradion
strongly recommends that this first optical surface is kept extremely clean by
mounting it in a tube that mounts to the face of the laser. The airflow from the laser can
be used to purge the tube. The tube must have an escape hole(s) for the airflow. The
holes should be halfway between the first optic and the face of the laser. If the back-
pressure is too high, the laser will fault so the total area of the hole(s) should be
between
≈ 50 mm
2
and ≈ 100mm
2
.
In addition, this first optical surface should be at least
20 cm from the face of the laser.
This will help reduce the possibility that any explosive failure of the beam expander or
other optic does not blow debris back into the laser and destroy the laser window.
By positioning a beam expander away from the laser, the beam quality can also be
improved.
Failure to fully protect the optical surfaces of mirrors and lenses positioned within 50 cm
of the laser face will result in damage as dust and smoke accumulate on them. Smoke
and fine dust will also alter performance of the antireflective coatings on lenses allowing
large reflections that could damage the laser or cause strange optical effects, including
pulsations of the beam and mode distortions.
Any reflection of light directly back into the laser must be avoided.