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Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

daguin said:

The 19% difference in output on the unit I reported is a direct replacement of the lens in the same laser (glass at the bottom, acrylic at the top of the diode retainer)

Peace,
dave

Click to expand...

That's an interesting bit of information, because my 30% difference in the readings of 3 different diodes (PS3, 6 X, and 830T), were compared against the Meredith acrylic. Which since then, I have discovered that the Meredith acrylic coating, is bad for the blu-ray, and gives less output than the AixiZ acrylic.

The difference for the open can red builds, is similar to your findings. About 20%, between the Meredith acrylic vs the Meredith glass...
Jay

P.S. If I had earlier stated that my comparisons with the Meredith glass, were done against an AixiZ acrylic. I had assumed that the Meredith acrylic, was the same as the AixiZ acrylic. This is because they are with the red diodes! But not with blu-ray! So, I have adjusted my thinking here. But there is a 30% difference between Meredith acrylic vs Meredith glass, using blu-ray diodes...
Jay

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

jayrob said:

As far as the Meredith glass lens, you can see from these pictures why it is giving more power. Because of the 'short focus' design of the lens, it has to set at the bottom of the brass holder, which positions it very close to the top of the LD!
Jay

P.S. You just gave me a great idea though! I think I will compare my readings on a blu-ray with an AixiZ acrylic in a Meredith module, and then drill out the 5.1mm opening at the bottom to a larger opening! (since the acrylic lens sits at the top, I can drill this opening out)

Click to expand...

Thanks for the pics and the info Jay! The 5.1mm opening is the same as the opening in an AixiZ lens nut retaining ring, when you cut it open.. So i guess there is no difference. The effective diameter of acrylics is not more than 5mm anyway.


The reason the Meredith is so good is not only it's distance from the diode... The distance is only part of the "light collection equasion".

The amount of light collection is determined by the Numerical Aperture of the lens - and the NA is a factor of two things: the focal length of the lens (and with it the distance from the diode), and the effective diameter of the lens...

Acrylics have a NA of 0.3, which is not enough to collect all of the light cone.. The Meredith has a NA of 0.53 (almost double). This is the main reason it is so good, along with the glass material of course. As long as the NA of a lens is the same or bigger than the NA of the diode, the lens will collect all of the light.

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

jayrob said:

P.S. If I had earlier stated that my comparisons with the Meredith glass, were done against an AixiZ acrylic. I had assumed that the Meredith acrylic, was the same as the AixiZ acrylic. This is because they are with the red diodes! But not with blu-ray! So, I have adjusted my thinking here. But there is a 30% difference between Meredith acrylic vs Meredith glass, using blu-ray diodes...
Jay

Click to expand...

Wait, so the 30% increase with the Meredith glass is when compared to the 650nm AR coated Meredith acrylic lens? That makes more sense now....

In that case your multiplier is a bit more off than assumed... Probably because you didn't factor in the AR coatings, when you calculated it according to DrLava's graph, that was done with a clear acrylic?


I thought you squeezed an AixiZ acrylic into the Meredith module.. Oh well....

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

IgorT said:

[quote author=jayrob link=1212910842/24#32 date=1213462467]P.S. If I had earlier stated that my comparisons with the Meredith glass, were done against an AixiZ acrylic. I had assumed that the Meredith acrylic, was the same as the AixiZ acrylic. This is because they are with the red diodes! But not with blu-ray! So, I have adjusted my thinking here. But there is a 30% difference between Meredith acrylic vs Meredith glass, using blu-ray diodes...
Jay

Click to expand...

Wait, so the 30% increase with the Meredith glass is when compared to the 650nm AR coated Meredith acrylic lens? That makes more sense now....

In that case your multiplier is a bit more off than assumed... Probably because you didn't factor in the AR coatings, when you calculated it according to DrLava's graph, that was done with a clear acrylic?


I thought you squeezed an AixiZ acrylic into the Meredith module.. Oh well....[/quote]

No no... I have several different set ups. All of my readings now are done with AixiZ acrylic, or Meredith glass. But early on, when I did the direct comparisons (with the same diodes) between acrylic vs Meredith glass, it was Meredith acrycic, not AixiZ...
Jay

P.S. Now that I have a blu-ray build, using an AixiZ acrylic installed into a Meredith module, I can do a comparison against a Meredith glass vs AixiZ acrylic.... I'll get back with the results!

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

Thanks! I just wanted to ask for that. It would be good to know the real percentage.

Since you have the acrylics holders for Meredith, can you just stick an AixiZ acrylic in there? This way, the comparison would be with the same diode....

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

Ok....with my 2 X blu-ray set at 110mA's. I am getting 94.9mW's with an AixiZ acrylic lens. (mounted into a Meredith module)

When I switched to a Meredith glass lens, I got a reading of 107.6mW's. Which is only about a 13% increase.

I recorded a 30% difference between Meredith acrylic vs Meredith glass. (earlier, with 3 other blu-ray diodes)

The difference between AixiZ acrylic vs Meredith acrylic is huge with the blu-rays. The two acrylics are about equal using red diodes...
Jay

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

That's what i feared... I excluded all other possibilities for an error, except for the possibility of the AixiZ acrylic actually being a Meredith acrylic..

Well, at least now i have actual data to work with.. Thanks!

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

IgorT said:

That's what i feared... I excluded all other possibilities for an error, except for the possibility of the AixiZ acrylic actually being a Meredith acrylic..

Well, at least now i have actual data to work with.. Thanks!

Click to expand...

The other thing to consider, is the use of different meters. For instance, I sent a Red burner to Senkat that I measured at 258mW's. He got 288mW's with his thermal meter!

I recently sent a Kryton blu-ray build to a good man in Denmark. He has a couple of different meters than mine. So I will soon have his comparison of my blu-ray build!
Jay

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

As long as the response of a meter is linear, the accuracy of the conversion factor doesn't matter for the percentage.. The relative measurement is correct, even when the absolute numbers are off. That is because they are off for the same percentage.

What i don't understand is where the 30% are from, because last time you said the Meredith acrylic causes this same laser at the same current to have 63.2mW, and to 107mW with the Meredith glass, that would be 70% more.

I'm talking about this: http://www.laserpointerforums.com/forums/YaBB.pl?num=1210968450/204#208

Do you remember this?

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

IgorT said:

What i don't understand is where the 30% are from?

Click to expand...

You're making yourself crazy IgorT. Relax. The lenses will be here soon. You will have the test done very quickly after that.

Even if they are ONLY as good as the Merideth glass lens, I will be happy, because I will be able to put them into an aiXiz housing. Then I can use them in many more places than I could in a Merideth housing.

Peace,
dave

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

IgorT said:

As long as the response of a meter is linear, the accuracy of the conversion factor doesn't matter for the percentage.. The relative measurement is correct, even when the absolute numbers are off. That is because they are off for the same percentage.

What i don't understand is where the 30% are from, because last time you said the Meredith acrylic causes this same laser at the same current to have 63.2mW, and to 107mW with the Meredith glass, that would be 70% more.

I'm talking about this: http://www.laserpointerforums.com/forums/YaBB.pl?num=1210968450/204#208

Do you remember this?

Click to expand...

Yes...you are correct about this being the same laser Igor. I do not have an answer to why the differences there. I can tell you that I used the same meter, with the same multiplier under all the different circumstances...
All at 110mA's with the 2 X diode:

Meredith acrylic lens - 63.2mW's
AixiZ acrylic lens (in a Meredith module) - 94.9mW's
Meredith glass lens - 107mW's

One thing that could help explain the difference, is the fact that there could be quality control differences between each lens. I noticed this before with the Meredith acrylic lenses. In fact , I noticed this a while back (Nov. of last year) with the reds. Gazoo had found the Meredith acrylic to be better than the AixiZ acrylic, and I found the opposite. Then I tried a different Meredith acrylic lens, and found it to be better than the AixiZ acrylic:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1195437700
Not sure why the differences between Meredith acrylics. Maybe the AR coating was heavier on one, than the other...

I have noticed that the AixiZ acrylic lenses, as well as the Meredith glass lenses, seem to be very consistent so far...
Jay

P.S. The 30% difference that I recorded with three other diodes (PS3, 6 X, and 830T), were between the Meredith acrylic vs the Meredith glass lenses. Those three diodes gave the same percentage of increase under different circumstances. (current/diode) But of course, using the same multiplier.

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

Ok, thanks for the info!

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

daguin said:

Even if they are ONLY as good as the Merideth glass lens, I will be happy, because I will be able to put them into an aiXiz housing.  Then I can use them in many more places than I could in a Merideth housing.

Peace,
dave

Click to expand...

I'll second that! We are very much looking forward to these 405nm coated glass lenses Igor!

As Dave pointed out, we want to put them into the AixiZ nut... If they turn out even close to the Meredith, I am in for at least 4 or 5 of them!
Thanks for your work!
Jay

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

Thanks!

Well, when i gave the production a go, i did not have any expectations in percentage anyway. I just wanted to get a great lens for Blu Rays at a reasonable price. And now that i have all the specs, i know that i will be happy with them, regardless of the actual power, because whatever it will be, it will be as good as it gets...

The only thing driving me crazy are all the questions, if i know what the power will be..... :
I should have just kept saying "No!".



P.S. I just stayed up all night doing the work (with the deadline in a few hours), that will pay for the prototype lenses.. I think i'm just under too much stress....

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

IgorT said:

Thanks!

Well, when i gave the production a go, i did not have any expectations in percentage anyway. I just wanted to get a great lens for Blu Rays at a reasonable price. And now that i have all the specs, i know that i will be happy with them, regardless of the actual power, because whatever it will be, it will be as good as it gets...

The only thing driving me crazy are all the questions, if i know what the power will be.....  :
I should have just kept saying "No!".



P.S. I just stayed up all night doing the work (with the deadline in a few hours), that will pay for the prototype lenses..  I think i'm just under too much stress....

Click to expand...

It's all good Igor...

We need to keep in mind that there will be variations in individual diodes too...

I'm sure there will be some variations in lenses as well. (even the same type lenses)

But it seems that there are different readings, from different meters too! Optical meters vs thermal meters and so forth.

As I told you in a PM, I just sent a Kryton blu-ray build to Erling in Denmark, he has a couple of different meters, and will let me know how my readings compare to his! I will share his results...
Jay

Re: F.S. Mini 'Pocket Pal' Blu-ray Lasers! - 90mW'

And I see a nice machinists tool box with a set of sockets for the car. Guitar, cars, rock and roll what else could there be.....lasers?