BiBO Crystal Handling
The
susceptibility to moisture of BiBO is very low. However, users are advised
to provide dry conditions for both use
and storage of BiBO to prolong the lifetime. Water condensation on crystal surfaces should be
absolutely avoided at any time.
Cleaning the Crystals
Dust and stains on crystal surfaces can cause
scattering/loss of light and can even react with light to damage optical
surfaces at a high incident laser power.
You can inspect the crystal surface for dust
and stains by holding it near a bright visible-light source. Viewing at
different angles helps to see scattering from dust and stains. The crystal
surface has to be cleaned if dust and stains are found.
You should perform the following cleaning
procedures in a clean, low-dust environment while wearing powder-free gloves
or finger cots.
1. Blowing off the crystal surface
A canister of compressed N2/clean air or a blower bulb (http://www.adorama.com/GTRABS.html )
should be first used to blow off dust and other loose contaminants. If a dry
nitrogen line is available in the lab, an air gun can also be used to blow
away dust particles. Blow off the surface gently. Do not blow off the
crystal itself from your hand !
2. Drop and Drag Method
Hold the crystal so that the crystal surface is horizontal and
slightly
above your fingers. Take a fresh, clean sheet of lens tissue and place it on
the crystal. Make sure the lens tissue can be drawn across the crystal
surface. Next place a small drop of pure isopropyl alcohol (IPA) on the lens tissue on top
of the crystal surface. The weight of the solvent will cause the lens tissue
to come into contact with the crystal surface. Slowly but steadily drag the
damp lens tissue across the crystal surface being careful not to lift the
lens tissue off of the surface. Continue dragging the lens tissue until it
is off of the surface.
The amount of the solvent can be adjusted for
various crystal size so the lens tissue is kept damp for the entire drag but
there is not any visible trace of solvent on the crystal surface after the
drag is finished. Inspect the surface and repeat if necessary, but only use
each sheet of lens tissue once.
If the crystal surfaces are still “dirty”
after the above cleaning procedures, the surfaces might have been damaged.
Please contact us for rework of the
crystals.
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