Boil Tests

[Alchemist]

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[mauroventura]

Has anyone ever found a red discolouration around the outer zones of AR coated lenses after a salt water boil test? If so, does anyone know the cause and possible solution?

This defect, sounds like a last AR layer problem!
Which kind of materials do you use for you AR coating ?
Which kind of Vacuum plant do you have?
is a IAD process your AR coating?


Mauro Ventura

[Alchemist]

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[mauroventura]

Thanks for your reply.

Our stack uses SiO2, ZrO2, Al2O3 and a hydrophobic topcoat pill. The machines are from Leybold, and use diffusion, roots and rotary vane pumps. They also have Meissner traps and an ion source, which operates at the beginning (substrate cleaning), and just before the topcoat stage. Layer thickness is determined by a central quartz crystal arrangement.

I have tried to recreate the red colour on a multi-layer computer program by changing the properties of the last layer. So far I have to admit that I do not have a convincing explanation of what is happening.

Best Regards,

Alchemist

... Leybold ? ... Brilliant process ? Diffusion pump ??

You can try to check the reading of your penningvac gauge if signs the correct vacuum .
Sometimes the penningvac gauge doesn't read the correct high vacuum for dirty particles coming from process materials and oil backstreaming from diff pump (in fact if i remember well the penningvac gauge is very near to the diffusion plate valve).If it's so the process start in no correct vacuum condition.

Hi

Mauro
I

[Alchemist]

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[Opti-god]

I have heard about some amateur in England who wait for it actually uses a sauce pan with just water and no salt to complete a salt water boil test the best bit is he has a camping stove to control the temperture, has anyone else every heard something so preposterous I can not believe this is true.

Anyway what is your salt water test precedure as I am sure you will agree this will have a major factor to your test results.

[Alchemist]

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