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ArcticMyst Security by Avery

Best lens for Blu-Ray?

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Feb 28, 2008
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Hello :)

Having built my first 803T high-power BluRay(87mW current- should be around 80mW ;D), I'd like to know what lens is best. I have 3 types here:

1) Aixiz glass- has a bluish coating on it.
2) Aixiz acrylic- can't tell if it coated or not honestly.
3) Sure Electrinics from 5mW red module- seems to be a reddish coating and I'm sure is not good for BluRay.

I have no meter to test with, and visually/burning ability-wise it is almost impossible to tell the difference. It is also my understanding that there are lenses specifically coated for blue, but they are rare and expensive. Also I understand the coating can be removed from the glass lens, but how safely?

Suggestions? I figured a thread on this would be nice so we have this info all in one place. [smiley=thumbsup.gif]
 





daguin

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My guests are going to be coming later than anticipated. I was able to do a quick test with my Milos unit.

Sure acrylic lens back not cut out = 21mW
aiXiz acrylic lens back not cut out = 21mW
aiXiz acrylic lens with back cut out = 24mW
aiXiz glass lense with obvious blue "tint" = 19mW

Peace,
dave
 
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Ok.. The Aixiz glass lens is OUT for BluRay:(.. I sacrificed one of mine(disassembling proved to kill it), and found 3 lenses inside. ALL THREE have coating on BOTH sides..the same blue-reflecting coating.. it is no wonder they cause such a drop in power. There is most likely no practical way to remove the coating from all three of these lenses without destroying the whole assembly.

I was online thru yahoo with jake21, and his tests resulted in a 8mw(62 to70) gain by just changing to the Aixiz acrylic lens.

I hated killing the lens to get it apart, but it was only a $3 sacrifice at least :-/
 

jayrob

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scopeguy20 said:
Hasn't anyone tested the Meridith Glass lens?

I compared my 6 X blu-ray, as well as my PS3 blu-ray between a Meredith acrylic and the Meredith glass lens.

For both diodes, you can multiply the acrylic lens reading by a factor of 1.3. It is a 30% increase in power! ;)
Here's why:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1207011306/36#36
For red open can diodes, the increase in power is about 20%.
Jay
 
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Glaserfan said:
Hello :)

Having built my first 803T high-power BluRay(87mW current- should be around 80mW ;D), I'd like to know what lens is best. I have 3 types here:

1) Aixiz glass- has a bluish coating on it.
2) Aixiz acrylic- can't tell if it coated or not honestly.
3) Sure Electrinics from 5mW red module- seems to be a reddish coating and I'm sure is not good for BluRay.

I have no meter to test with, and visually/burning ability-wise it is almost impossible to tell the difference. It is also my understanding that there are lenses specifically coated for blue, but they are rare and expensive. Also I understand the coating can be removed from the glass lens, but how safely?

Suggestions? I figured a thread on this would be nice so we have this info all in one place. [smiley=thumbsup.gif]
Under Companies sub-forum you will find a sticky for lenses with the correct AR coatings for blue wave lengths. You want a lens that is AR coated or a lens that has an index of refraction appropriate for that wave length.
 

IgorT

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That's what i want to know as well.

But i thought it was common knowledge by now, that the clear one is always going to be better, than a 650nm AR coated one.

Climbak revealed that after he discovered it. 650nm AR coating can halve the output compared to a 405nm coated one. Clear lens is almost as good as 405nm coated one, and untill we have those, it is the best choice, if you want the most power out of your laser.


There might be some weird lenses somewhere, that are AR coated for a different wavelength but would work for 405nm, but for now, the best bet is a clear lens - more power at a lower current! Instead of pushing the current, use a clear lens! It's as simple as that.
 
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How do you tell if its coated or not? Is it obvious? and what would the color of the coating be?
 

IgorT

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cbrian4 said:
How do you tell if its coated or not? Is it obvious? and what would the color of the coating be?

You just look at it. AR coated lenses have a blueish tint to them at certain angles.

If your modules are from DX, they have a clear lens. I just discovered my only 650nm AR coated lens is in my Dilda Lazor.


I made a quick test with different lenses, using a PHR-803T, running at 90mA.
>82mW - no optics
67mW - clear acrylic lens
62mW - 650nm AR coated AixiZ glass lens
40mW - 650nm AR coated acrylic lens

At 96.5mA i would get:
>98mW - no optics
76mW - clear acrylic lens (slightly dirty and scratched in the meanwhile, so i lost 4mW would have been 80mW if it was a fresh lens)

Don't want to do other tests now, so as not to let any more dust between the diode and lens.


As you can see, an AR coated acrylic actually halves the output! But it would seem the material is part of the problem as well, since the glass AixiZ lens is really three lenses, each with double sided 650nm AR coating....

It is surprising, that the glass lens puts out so much 405nm after all the coatings. Glass is obviously very good for 405nm, so if it wasn't coated, it would work great!

Plastic would seem to be part of the problem by itself. Combined with an AR coating it then halves the output.
The best thing for 405nm would of course be a 405nm AR coated lens.
After that, the next best thing would be a clear glass lens or a Meredith glass lens (even tho it is AR coated for reds).
Place three goes to a clear acrylic, which is not that bad actually.

With a good diode, a clear acrylic can put out 80mW at 90mA (My first diode would seem to be a little weaker).



I hope this info helps someone.
 
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Does anyone know if the expencive lenses from thorlabs will screw into an aixiz housing? Or even if the head of the kenom barrel can be tapped out or heli-coiled to accomidate one?
 

IgorT

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GooeyGus said:
Does anyone know if the expencive lenses from thorlabs will screw into an aixiz housing? Or even if the head of the kenom barrel can be tapped out or heli-coiled to accomidate one?

You should ask climbak about that.. He has one of those $100 lenses..
 
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IgorT said:
[quote author=cbrian4 link=1211152516/0#9 date=1211431914]How do you tell if its coated or not? Is it obvious? and what would the color of the coating be?

You just look at it. AR coated lenses have a blueish tint to them at certain angles.

If your modules are from DX, they have a clear lens. I just discovered my only 650nm AR coated lens is in my Dilda Lazor.


I made a quick test with different lenses, using a PHR-803T, running at 90mA.
>82mW - no optics
67mW - clear acrylic lens
62mW - 650nm AR coated AixiZ glass lens
40mW - 650nm AR coated acrylic lens

At 96.5mA i would get:
>98mW - no optics
76mW - clear acrylic lens (slightly dirty and scratched in the meanwhile, so i lost 4mW would have been 80mW if it was a fresh lens)

Don't want to do other tests now, so as not to let any more dust between the diode and lens.


As you can see, an AR coated acrylic actually halves the output! But it would seem the material is part of the problem as well, since the glass AixiZ lens is really three lenses, each with double sided 650nm AR coating....

It is surprising, that the glass lens puts out so much 405nm after all the coatings. Glass is obviously very good for 405nm, so if it wasn't coated, it would work great!

Plastic would seem to be part of the problem by itself. Combined with an AR coating it then halves the output.
The best thing for 405nm would of course be a 405nm AR coated lens.
After that, the next best thing would be a clear glass lens or a Meredith glass lens (even tho it is AR coated for reds).
Place three goes to a clear acrylic, which is not that bad actually.

With a good diode, a clear acrylic can put out 80mW at 90mA (My first diode would seem to be a little weaker).



I hope this info helps someone.[/quote]

It looks like mine is clear! is the back of your acrylic cut away?
 

IgorT

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No, not cut away. Pulled out. I always pull it out.
That narrow opening in the original lens nut is horrible.


Keep in mind, that there are differences between diodes. They will not all put out the same power at the same current. The diode in my test measures without optics what Dr_Lava's diode measured with a clear acrylic lens (at 90mA at least).

My readings are on the other hand identical to what climbak got when he measured his diode's power without optics.


So they are not perfectly consistent, there is a certain power range, within which a diode will be at a certain current.
But without a meter, you can't know for sure. For now it would seem, that 90mA yields around 67-80mW after a clear acrylic lens, depending on the diode. A slightly dusty lens can also take 4-5mW off. I am very careful not to get any dust in between the diode and the lens.


I just hope i can get the special 405nm AR coated lenses soon. If i can, and the price is good, i might do a group buy. I just need to test if they work in an AixiZ module first.
 
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In addition to the 405nM-AR coating and ability to focus light at a given wavelength, (chromatic abberation?), my ideal 405nM lense would also have a little closer focal-length, to reduce beam diameter. I know this will increase divergance, but a little thinner beam, even with a little more divergance would be nicer to work with, and much more visible. ;D
If I collimate my PS3 diode/Aixis-glass lense to infinity, and shoot it through a 2x beam expander, backwards, I get beam properties very similar to my DX 30mW green lasers, very nice, but bulky.
I think the lenses in the modules are usually about 8mm focal-length, so if we could find a lense, coated for 405nM, which is "achromatic" for 405nM, with a 4-6mm focal-length, which would fit in an aixis module, we would be set! ;D Oh yeah, it should be free ;)
Dark Horse
 




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