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A plea to users of coated optics (G1 and G2) lenses






conversations evolve.. if they didnt we would still be talking about the first thing we spoke about. let it flow, let it flow, let it flow......:na:
 
That's interesting... I wonder if I could use some of that fungus to actually destroy some filters, for example on Bayer filters on CCDs?.
 
Back to our coated / non-coated debate. Got back the email from China, It was quite interesting.
OK...
ALL of the commercial diodes in projectors, Blu-ray and DVD-R are bandpass coated with a very thin transparent layer of a "unique" metal oxide. simular to that found in n@#$as (352673A AR 400-600nm) depending on the manufacturer. The coating does 2 things. It stabilizes the laser output from "mode hopping"/prevents efficient reduction of the gain chip cavity finesse, and also functions as an anti-reflection coating. Apparently this mode hopping isn't particularly a problem in multimodal diodes, such as our projector diodes and have another coating applied to the windows. They are only AR coated.

Contact in China explained clearly... NEVER touch a diode window with anything but a soft q-tip. The acids on your finger will weaken and eventually eat the coating off. Clean the windows with ethanol.

One more point, these diodes are coated to a point. They however they will NOT survive a direct reflection, doing so instantly causes damages the optical cavity.

I am surprised, Single mode diodes are prone to "mode hop" I had no idea... new to me.
 
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Tech_Junkie said:
This is common knowledge.


So are they all AR coated, or just the multimode blues? :thinking:
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...such as our projector diodes and have another coating applied to the windows. They are only AR coated.
Click to expand...

I was just reiterating/ illustrating the point in which the AR coating is durable.

Projector diodes have an AR coating only. apparently they don't need the stabilization that single modes do..
so they utilize a totally different material for the diode window.. Again, this is what was relayed to me.

Just about ALL the diodes we would encounter are AR coated.



I will post hopefully some info regarding coating materials soon. Could be good for a read.
 
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Can we get back to the G1 and G2 lenses now? :o

Maybe we can have a couple more lens owners to take a beam shot with the lens just barely screwed on the module--this makes the resulting beam wide enough to show discernible patterns, if any.

Also how bad is a 14" splash at 4.5 feet (white surface) from a 2.3W H1600?
 
Actually, I managed to clean up an old coated glass Aixiz lens from 2 years ago that had a mild amount of spotting on the lens.

The trick is to use hot (60c) ~40% Alcohol (Ethylene) on a hot plate with good ventilation and a clean optics cloth. You'll also want to use solvent proof gloves.
I managed to get pretty much all of the spots off the lens. An ultrasonic cleaner with a heater built in works very well.
IF this doesn't clean your lens up coating has been compromised. Hence the case of how the thread started.

Lenses that have cleaned up nicely are 2 Aixiz lenses, 2 Olike coated glass lenses and my RHD 450nm G1 lens. G1 lens is 100% clean. no spotting whatsoever.

My storage case has 3 packets of Silica Gel now so that no organisms can do damage to my lenses when the weather gets humid.
 
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Take a swap, put it on some agar in a petri dish and ship it off to WL:eg: Maybe they can take a closer look into how to remove them from lenses:shhh:
 
Actually WL isn't involved with the G1 lenses.
I am still curious why NIKON optics indicated
fugal damage to a single lens. Again, I am under the impression
the damage is occurring in storage.
 
lazeristasUVISIR said:
There are spatial modes and longitudinal modes.
I assume that a longitudinal mode would jump when there is a parasitic non-steady reflection coming from the window.
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Actually got another reply from China (OSRAM) about this and you're dead on the money.
Exactly. The parasitic reflections indeed are why coatings have to be very special on single mode diodes specifically. Multimodes don't mode hope and only require a single coat for proper transmission through quartz widows.
 
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I managed to clean up my G1 with a Chinese ultrasonic cleaner for about $20 using regular water. There are still visible spots when completely defocused but a lot better than before. The focused dot splash has also considerably been reduced almost 90% (previously 14" wide on a white painted surface) but some "satellite" reflections have developed about the same radius as the previous splash.

On an additional note, the burning capabilities have also considerably improved.
 
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TomD said:
I managed to clean up my G1 with a Chinese ultrasonic cleaner for about $20 using regular water. There are still visible spots when completely defocused but a lot better than before. The focused dot splash has also considerably been reduced almost 90% (previously 14" wide on a white painted surface) but some "satellite" reflections have developed about the same radius as the previous splash.

On an additional note, the burning capabilities have also considerably improved.
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DO NOT use water on those lenses. These are Coated with MgF2 and will deteriorate with moisture. Especially since you live in a humid climate, this can encourage some growth of fungi to grow on the inner/outer surface. Also, eventually moisture can react, inside the lens housing and become acidic enough to eat the coating around the edges of the lens.

use Ethylene, you can also, more beneficial to use 200 proof USP which contains almost no H2O. 98.9% or something along those lines... Actually, come to think of it DON'T ever use Methylene as it can dissolve a few of the coatings for optics.
Also attacks Aluminum mildly.
 
Seoul_lasers said:
DO NOT use water on those lenses. These are Coated with MgF2 and will deteriorate with moisture. Especially since you live in a humid climate, this can encourage some growth of fungi to grow on the inner/outer surface. Also, eventually moisture can react, inside the lens housing and become acidic enough to eat the coating around the edges of the lens.

use Ethylene, you can also, more beneficial to use 200 proof USP which contains almost no H2O. 98.9% or something along those lines... Actually, come to think of it DON'T ever use Methylene as it can dissolve a few of the coatings for optics.
Also attacks Aluminum mildly.
Click to expand...

Well that's a lot of things the lens shouldn't interact with. I'll go check where I can get some pure ethylene locally.

I keep blasting the lens with compressed air from time to time. Is that also bad?

The G2 doesn't have the MgF2 coating. Maybe it's a much better lens after all.
 
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