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ArcticMyst Security by Avery

405nm AR glass lenses - fit AixiZ  FEELER

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Hey Igor!  I would be glad to get a broadband lens!  Just let me know when to send $.  (I will still need 2 lenses, at least from the 405 nm optimized run!).

I would order 2 broadband lenses, but $ is short as, I have too much $ tied up in a 803T GB.
 





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Yeah me to, like I already said a few posts above, I am in for a broadband, thinking of using it on an open can build after the 405 lenses come in, until then it will be my blu-rays companion.

How many more interested do we need on the mini-GB to get it moving? If needed I can take an extra broadband, quality lenses are always useful.


Thanks
brtaman
 
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Re: 405nm AR glass lenses - fit AixiZ  FEELER

IgorT said:
Unfortunatelly, there is no way i can take Google Checkout. I live in Slovenia. In fact i still haven't even tried getting money out of PayPal. You can't link a bank account here. The only thing i can do, is extract the money onto a credit card.

That can be a problem since I don't use paypal. Anyone here mind if I pay you through the google checkout and you pay igort though paypal?
 

IgorT

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

For a while, i was considering another option.. Someone in the US collecting all the money, using Google Checkout/whatever, and then wireing the money to me. That is if i couldn't get it out of PayPal myself.


Otherwise, i'm sure something could be arranged, but it would double your fees.
 

Kage

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I would be willing to buy 2 of these initially just to help out ;)
Then maybe 10 or 20 down the line in a big group buy if they work good.
 
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Whats the difference between a 100mW Blu-Ray with a 405nm coated lens. And one with a broadband lens?

And how well will the broadband lens perform with 473nm, 532nm, 594nm, 635nm, and 670nm wavelengths?

I would be willing to take 15 if that many are still available.
 

Krutz

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

i didnt read all of the 19 pages yet..

-what would be shipping to germany?
-is paypal-payment possible?
-what do you think will be shipping-date?

if its 23$ for the multi-coated lenses, i think i'll take two.

thank you for your effort on this, great! and first time for diy-hobbyists too! :)

manuel
 
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Re: 405nm AR glass lenses - fit AixiZ  FEELER

I would take 2 of the small batch if there are still some spots. One you could put in the laser you are building for me, and one for whenever I build my project. :)
 

LarryQ

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Hey IgorT...

I'm still up for (4) 405Nm Coated .....just waiting for payment options and A total with Shipping to Oklahoma City, Oklahoma.

Too Cool...and thanks for all your efforts!

LarryQ
 

IgorT

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Krutz said:
-what would be shipping to germany?
-is paypal-payment possible?
-what do you think will be shipping-date?

Krutz:
Ich habe das Gefuehl, das Versand nach Deutschland nicht all zu viel kosten wird... ;)

Shipping will be cheap for anywhere, even with priority. It's the registered part that makes it expensive, but we probably don't need tracking numbers, do we? I could have it as option, if someone is worried tho.


PayPal will be the only payment option possible (unless someone else collects the payments and wires the money to me), as due to where i live (Slovenia, EU), even PayPal is hard to turn into actual money. The only option i see is pulling it out on a Visa card. But it can't be my company Visa, so i am having a personal one made just so i can finally start getting money out.


Shipping date? After i collect all the money, and make the order, i will have the lenses in about a week and a half. I will start collecting payments shortly before my Visa card is ready.

Untill then, i will give everyone a little more time, to consider joining the mini-GB for broadbands.
So if anyone else wants, please expres your interest here, and by the time i'm back up and running, i think we can start collecting orders.


I am keeping my online times very short at the moment. Altho my eye is almost back to normal, one of the drugz i was getting in there was meant to immobilize my pupil for weeks, so it would rest. As a result, it is still impossible for me to read using both eyes, and if i keep one closed it all starts hurting.

At the same time i am busy with making up for the lost week, so i mainly only check my email and PMs.. (If there is anything urgent, please email me.)



Some of you have asked if it is still possible to order X amount of broadband lenses, or Y amount of 405nm lenses. Yes, there IS still time and room for both!

The mini GB for broadbands is not limited to 40. We can go up to 80 without losing the special coating price. That would halve the coating cost per lens, and even the lenses themselves could become cheaper, and we might actually get them down to $23 a piece. But it will take more than 40 for that.

However, it would seem, that Midknight and I would take almost 40 by ourselves.. And there are other people interested. So this is starting to look better and better! ;)


Midknight:
For a 100mW blu ray (assuming the diode is putting out 100mW, not that 100mW is power after plastic lens), the difference would be ~0.8mW.. Remember. The broadbands are R<1% and the 405nm ML ones are R<0.2%. So the difference in reflective losses is ~0.8%.

If it's about a blu ray, that is putting out 100mW after a plastic lens, then the expected power after a broadband would be 116.5-120mW (guessing, to many variables - more on this later). In this case, the difference between the broadbands and the 405nm optimised ML would be ~1mW


Oh, and you asked which wavelengths the broadbands would work for. They are made for 400-700nm. They cover the entire visible spectrum. The R<1% means, that within this range the reflectance is under 1%. At some wavelengths it's less, at others more, but at all of them it is less than 1%.

So yeah, it would work for all wavelengths in this range.



I have some more lens specs, btw..

The old lens (the spherical disaster lens) was made of a material, that preforms poorly at 405nm. A 10mm slab of glass has an internal transmittance of 0.857.. That means 85.7%, translating to 14.3% losses by the time 405nm passes 10mm of it.

Of course the lens is not 10mm thick, but has a thickness of 2.5mm. This means the losses are 1/4 of the losses in a 10mm slab, or 3.575%, resulting in an internal transmittance of 96.425%.. So even tho it's "bad", it's not that bad at only 2.5mm. The coating was R<0.5%, meaning 0.5% or less reflective losses, resulting in a total lens transmittance of 95.952.. Since R is less than 0.5, the total transmittance of a coated lens is 96%.

Usually, good lenses (like the Meredith glass) have 95% transmittance at the wavelength they are optimised for, so relativelly speaking, that lens would not be bad, if only it wasn't a spherical lens. The low transmittance was a result of the FL demands. It was only possible to achieve with this material. Not that it matters at this point.. :(


But the aspherical lens we are getting now is made of a different material, which behaves very nice at 405nm! A 10mm slab has an internal transmittance of 0.995! That's 99.5% at 405nm. At 660nm, it is even more - 99.9%!

Now that's as if the glass is not even there! I have seen air with a lower tansmittance! ;)

And that's for a 10mm slab. The lens is thinner, so again the losses are divided by 4, resulting in the lens having an internal transmittance of 99.875% for 405nm and 99.976% for 660nm. This could almost be rounded off to 99.9% for blu and "100"% for red...

Now that is INTERNAL transmittance - once the light is inside. But it needs to get inside first. That's where reflections come into play. Hence the AR coating. But no coating is perfect, and it only reduces reflections, not removes them completelly. A little is still lost as reflections, even with the best coating.

- The broadband coating will reduce them to <1%, so <1% is lost in reflections, and we get 98.88% for blu and 99% for red. Now this is not at all bad even with the broadband coating.
- The 405nm ML coating will reduce reflections to <0.2%, so we get 99.68 for blu, unknown at the moment for red, but could still be usefull. Won't be as good as broadband for reds tho... (Still need to get the graphs, to extrapolate the reflectivity at other wavelengths)


Now if only the numerical apperture is large enough to collect the entire cone of light, this lens will be absolutelly PERFECT!


The interesting part for me is this:
I have a PHR blu ray doing 165mW after a plastic lens.
There is more power behind the lens, but some gets lost in plastic, and some gets reflected back into the diode
After i put in an AR coated lens, the power will be increased.
Let's say, the increase is only 16.5% (it will vary, more on this later) Now my laser is suddanly 192mW!
But at the same time, the strain on the diode is decreased, due to no reflections going back in.

Now this means that i just increased my power dramatically, but at the same time i made it easier for my diode! My laser is now more powerful and will live longer at the same time!

However, let's say, that i am comfortable with the risk i had when it was doing 165mW after plastics.. I know, that reflections from an uncoated lens are usually 7-8%. with the broadband coating the reflections are under 1%.

What this means is, that i can now further raise the current, till the diode is putting out 6% more. Due to reduced reflections, the optical flux at the die is now the same as it was at the lower current setting, when i still had the plastic lens in.

So, my power was already increased to 192mW, and i just increased it by 6% more. Suddenly, my power is now 204mW! And yet, the strain on the diode is no higher, than it was, when it was only putting out 165mW after a plastic lens!


So i just went from 165 to 204mW, that means the lens allowed me to reach 23.6% more than i had before, and at the same risk! And this was a conservative example. The increases i have measured with the spherical lens were 16.5 - 19.5%. So it can be more, especially since the new glass is so much better...

On the other hand, i could just decide, that 192mW is good enough, and leave it at that, and enjoy the benefits of the lower risk instead..


Interesting possibilities, huh? ;)



Anyway, need to log off. I'll give everyone a bit more time to make their decisions, and then we can get this started...
 

artix

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Cool! :eek: how many mAs do I need with the broadband lens do I need to get 200mW of bluray? (I don't care if I kill one, they're so cheap! [smiley=evil.gif])
 
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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Sheeeot, well with those kinds of stats, can you change my order to four (4)? Might as well deck out all my Kryton barrels with great lenses.
 

IgorT

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Artix said:
Cool! :eek: how many mAs do I need with the broadband lens do I need to get 200mW of bluray? (I don't care if I kill one, they're so cheap! [smiley=evil.gif])

Well, this depends. Diodes vary in efficiency a lot.

The diode in my example is a freak. It is doing 165mW at "only" 160mA. After the lens it could get to 192 or it could even get to 200, without even raising the current! That's because the increases that will come from the lens will vary. Not because the glass lenses would vary (they will be consistent), but because the plastic lenses vary. (i will explain this in detail later)


So if i'm lucky, this particular diode might even do 200mW after the glass lens at only 160mA. Not very likelly, but possible. Or maybe i'll have to increase the current by 8mA....

Normal diodes need much more current to reach powers like that. That's because they have a lower slope efficiency (differential efficiency - current(minus treshold current) vs. power). Then there are weak diodes, that can not reach these power levels at all. I have pushed one like that to 190mA and it only reached 134mW after plastics.


So, without a meter, it is impossible to tell what a diode is doing just from the current. And it's impossible to tell how much current a diode will need to reach a certain power, without measuring it.

If you look at my PHR batch testing thread, i have gone through 61 PHR diodes, testing them all at the same current, and the powers come out all over the place. And then, two that measure in at the same power at one current can have a completelly different powers at another higher current. That's because their slope efficiencies are different and the graphs only intersect at the lower current by chance.

There is an average power for every current. For example at 109mA you get 90mW on average, but actually you can get 90+-17mW. And at higher currents the differences become larger. Obviously i can't test and plot graphs of all the diodes at all currents, but instead, i tested the lowest and the highest efficiency diode i have at several currents. I still have to test higher currents, and then i can post ranges you can expect from the PHRs at various currents.



In any case, the lenses will not only increase the power, they will make the increased power safer for the diode. Or allow you to further increase the current without increasing the risk.

Basically, the lenses will make overdriving safer, by reducing the reflections to less than 1% (broadbands). The 405nm optimised lenses will reduce reflections to less than 0.2%, which can really be considered as no reflections at all. At 200mW only 0.4mW would get reflected/lost.

Since i also have these same lenses uncoated, i will be able to measure how much reflections actually are. Generally accepted figures are ~7%, sometimes it can be more, up to 14%, depending on the material and various other factors.

When you have a lens AR coated, the power that would otherwise be reflected back into the diode, now goes through the lens, increasing your output, and decreasing the strain on the diode.
 

IgorT

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

Bionic-Badger said:
Sheeeot, well with those kinds of stats, can you change my order to four (4)?  Might as well deck out all my Kryton barrels with great lenses.


Are you still getting 405nm ML lenses after that? Cos if you are, you don't have to take too many in the mini-GB.

The idea behind the mini-GB is, that we each take a few, so it amounts to a number, that gives us a decent price.
But it should still be considered as a test before the final order


The specs i gave are correct. But they are for transmittance. There are still other factors in play here. One of them is the NA (numerical apperture). It determines how much of the diode output the lens will collect.


I still have one complicated task ahead of me. I have to get one of the uncoated samples ground down to 7mm dia, in order to test the mounting and positioning of the lens. At that point, i can also test the amount of light collection, simply by setting the lens to parralel focus, measuring the power, moving the lens closer to the diode and measuring again. Ideally, the power should stay the same, or increase very little.

If this works out, it will be a great lens!
 

Krutz

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Re: 405nm AR glass lenses - fit AixiZ  FEELER

that sounds great!
with that low difference between the 405 and broadband-coating, who would buy the 405-only one at all? i prefer to be able to swap them out into my new 500mw red, once its available and cheap, and i am bored with violet.. ;-)
so, cant wait for this to start, and to get my two broadband lenses! :)

uhm, arent there different "aixiz lenses", diameter-vise? i use the small 12mm brass module, and seem to be the only one..

manuel
 




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