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

[Seoul_lasers]

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.

Compressed air is just fine. I wouldn't be so sure about the G2 lens not being MgF2. MgF2 is very cost effective compared to other lens coatings. Some of the more professional lens coatings are $100's each!

G2 lens seem to have a horrid splash pattern... not sure why. G1 lens I have is nearly perfect after giving it an hot Ethanol bath for a few minutes and polishing with an optical cloth.
Beam profile and splash have improved dramatically. Also, I see a slight reading increase now that the coating is cleaned. ~100-150mW.

 

[Tech_Junkie]

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.

IgorT always used Acetone for cleaning lenses. Also I've read, from a couple of sources, nothing less than acid would remove the coatings.

 

[31415]

Where can I purchase a lens (such as the G1 or G2) that will concentrate the power of a laser beam? Thank you.

 

[jayrob]

Where can I purchase a lens (such as the G1 or G2) that will concentrate the power of a laser beam? Thank you.

Shoot me a PM...

See here for slight differences in mounting for G1 vs G2:
http://laserpointerforums.com/f65/405-g-1-vs-405-g-2-a-73278.html#post1057003

 

[TomD]

I blew more comp.air and now the focused "dot" is a sharp bold line with thinner "wings" one slightly longer than the other. There's a bit of satellite ghosting around it but it is definitely brighter and more intense. When I first got my G1 lens, it wasn't this clear.

Is there a thread/gallery comparing G1/G2 "dot" clarity using different diodes?

 

[Seoul_lasers]

IgorT always used Acetone for cleaning lenses. Also I've read, from a couple of sources, nothing less than acid would remove the coatings.

That is true, acids will destroy the coatings. However, Methanol is extremely strong as far as solvents go. It all depends on what the lens is coated with. MgF2 is indeed safe with methanol, but other coatings may not be. I have no idea what other glass lenses are coated with. Methanol may in fact end up attacking the coating. What do we figure the newer G2 lenses are coated with? anyone?

A bit of an aside, actually, one company here in Korea, that is involved in making diodes suggested that they use a metal oxide to coat a few 400nm LD windows. IF this is the case, Methanol will end up removing the AR coating on the LD diode windows. So don't use it on diodes to clean the windows. Ethanol would be a better option.

 

[hakzaw1]

I recently read at another forum about the use of Q-tips when cleaning lenses.
Apparently some brands use a glue to keep the cotton on. And some solvents can dissovle this glue and there is a chance it can end up on the lens.

hk

 

[Tech_Junkie]

Good tip (pardon the pun) Len. :beer:

 

[DTR]

I recently read at another forum about the use of Q-tips when cleaning lenses.
Apparently some brands use a glue to keep the cotton on. And some solvents can dissovle this glue and there is a chance it can end up on the lens.

hk

Thanks for the heads up. I use Q-tips with alcohol all the time to clean diode windows. Have not had any issues yet but I will keep this in mind.:beer:

 

[Blord]

I use pharmacy alcohol too for cleaning lenses. Acetone is way too aggressive. It can melt any plastic and the fume can weakening it too.
The higher the percentage the better. I use the 97% alcohol. It even helps cleaning teeths and against bad breathe.

 

[piferal]

I use pharmacy alcohol too for cleaning lenses. Acetone is way too aggressive. It can melt any plastic and the fume can weakening it too.
The higher the percentage the better. I use the 97% alcohol. It even helps cleaning teeths and against bad breathe.

I recommend that if you use isopropyl alcohol, (or other) you do with a purity of 99%,
because lower concentrations may contain non-volatile additives which can leave
traces in the optics, maybe this is not very important in our handheld laser optics,
but in optics more delicate as those of your cameras, you know, yes

For your camera optics you know there are other ways before you get to use
solvents, first of all, don't dirty them, haha.

Here and here you have a 2 little guides for cleaning glass optics, one of
these is not specific to laser optics, but you can extrapolate much of it.

 

[Seoul_lasers]

I recommend that if you use isopropyl alcohol, (or other) you do with a purity of 99%,
because lower concentrations may contain non-volatile additives which can leave
traces in the optics, maybe this is not very important in our handheld laser optics,
but in optics more delicate as those of your cameras, you know, yes

For your camera optics you know there are other ways before you get to use
solvents, first of all, don't dirty them, haha.

Here and here you have a 2 little guides for cleaning glass optics, one of
these is not specific to laser optics, but you can extrapolate much of it.

Yup, Isopropanol (Isopropyl Alcohol) is great too. DO NOT use it with or around Acrylic as it will promote crazing.

 

[TomD]

Guys you can relax about the acrylics now. Let's go back to the borosilicate glass G1 and G2s.

Can anyone with a multimode post pictures of their wall dots with the lens just barely screwed in?

 

[Kizdawg]

CheeseWiz!!! Now I have heard it all!

Toe Jam for Lasers... Yikes...

:barf:

 

[sneaton]

i have a g1 lense in my laser....can i soke the lense in 91% isopropyl for a minute or so? my laser has a couple round spots in the unfocused beam...when i take the lense off the diode window is clean as a whistle so it has to be the lense...i tried using lens cleaner but theres still a couple spots....or is it impossible to get off every little spot...please help a laser noob

 

[Flaminpyro]

If you soak it the alcohol will seep into the inner parts and wet them then if there is any contamination in the alcohol or on the lens it will be carried in and deposited on the inside of your lens and stick there when the alcohol eventually dries out.

You need to have clean new alcohol to start, best to use 100% methyl alcohol, it's better at not leaving streaks since there is no water in it.

I suggest cleaning it with a Q-tip wetted but not dripping with alcohol.