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...
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])
