IPG IX-6168-PS, Hardware Reference Manual

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Maintaining the Workstation
12-2
Handling and Cleaning Optics
Keeping the optics meticulously clean makes them work more efficiently and last
longer.
Handling Optics
Always follow these rules when handling and cleaning optics to avoid damaging
them:
❑
Wear clean, powder-free latex gloves to handle an optic. Skin oil can damage
coatings and contaminate the optic so that it absorbs laser energy and is ruined.
❑
Handle the optic only by its edges, and never touch the surfaces.
❑
Use lint-free lens tissue to clean the optics. IPG Photonics recommends Kodak
brand.
❑
Do not reuse lens tissues.
❑
Do not treat lens tissues with any antistatic compounds.
Inspecting Optics
To inspect an optic:
✧
Look for surface contamination or damage. You can see scratches by holding the
optic at an angle to a room light to show surface reflections. You can also see the
coating (typically green or rose-colored) by holding the optic at an angle.
Coatings can also be seen when the optic is held at the appropriate angle.
✧
Look for material degradation, such as color center formation. Color centers can
be invisible under room light, so you should periodically inspect the lens while
holding it in the fully attenuated laser beam. (Magnesium fluoride tends to form
orange or blue color centers; UV-fused silica typically forms red color centers.)
Optic Failure
The optic may need replacement if it has visible pits or the shape of the laser beam can
be seen in its coating,
The most common cause of premature optic failure is dust on the optical surface.
When the laser beam passes through a dirty optic, the dirt absorbs beam energy and
causes thermal damage to the optical coating.