Cleaning Procedures for Infrared Optics
The following description for to clean IR optics does not apply to water soluble crystals,
highly hydroscopic materials, or certain other specialized materials:
Some examples are:
Simply put, these optics are cleaned as part of the polishing process, and would be damaged by further cleaning attempts.
They will be severely damaged or degraded by water, or by rubbing with acetone or alcohol cleaning products.
At best you can lightly brush them in order to remove dust or lint.
When they arrive at your facility, they should be clean. Take great care in keeping them clean.
Clean foam mat or other suitable cushioning surface.
Finger cots or gloves ( latex or cotton). Lens tissue or Tex-wipe,
Squeeze bulb, or dry filtered air or Nitrogen. De-ionized water,
Reagent grade Methanol, Acetone or Isopropyl alcohol.
Before handling or touching optics, it is very important to
understand basic physical characteristics of the material. Infrared
optics can be brittle or soft and can be easily damaged while handing
or transporting. Even if it seems negligible, slight damage can propagate
into a crack or ruin the performance of optics in a system. Oils from
fingerprints can easily damage or etch the surface of an optic and often
the damage cannot be removed. Therefore you should not handle optics with
your bare hands. Even if you wear finger cots or gloves avoid touching the
surface of the optics. Be certain that your gloves are clean and free of
contamination before cleaning. Allways hold optics on the edges or non
Cleaning of Coated Optics
Start by blowing of the surface of the optic to remove
dust or particulates which may scratch the surface.
The type of contamination on the surface will determine what solvent
will be most effective for removal. De-ionized water may be suitable for
common dirt or marks. Organic solvents may be needed to remove finger prints,
epoxies or resins from mounting. Use a lens tissue or Tex-Wipe and thoroughly
moisten with the appropriate cleaner. Gently wipe surface in a linear motion
slowly pulling wipe off opposite edge. If this is not effective, wipe surface
in a circular motion slowly pulling wipe towards the edge
and then off
If this is still not effective contact ISP for further information.
Inspection or Viewing of Optics
These are common inspection rules regarding physical evaluation of
surface quality and inspection methods, which most optics companies follow.
According to para. 184.108.40.206 MIL-O-675, optical component shall be inspected
using 15 watt cool white fluorescent light tubes and the viewing distance
shall be 45.7cm or less. Also it indicates how to examine optics at a
For more information about coating surface evaluation, please check
the following MIL-specifications:
- MIL-C-675 - Coating of glass optical elements
- MIL-M-13508 - Mirror, front surface aluminized: for optical elements
- MIL-C-14806 - Coating, reflection reducing, for instrument cover glasses and lighting wedges
- MIL-C-48497 - Coating, single or multilayer, interference, durability requirements
- MIL-F-48616 - Filter (coatings), infrared interference: general specification
ONLINE IR CATALOG
CUSTOM IR PRODUCTS