445nm Lens Comparisons!

[HIMNL9]

Re: 445nm A130 Lens Comparisons!

Thats the other thing that I was planning on experimenting with...

Taking apart an AixiZ 405 lens, and trying to take out the main optic and replace it with the 405-G-1 to see if it will clean up the 405-G-1...

But like you said... probably dreaming!

Do you mean exchange the main (first) lens with the 405 one ? ..... if so, i'm sorry to say you that this probably don't work (and can end in the destruction of the negative lens of the triplet, too)

Those lenses in the triplets are built with specific curvatures, and focal lenghts ..... changing one of them, or also just the distance between them, just make the things worse ..... they are matched for correct the lateral deformation in the lens assemblies, mainly for photographic use, and is for this reason that the dot appear more "round", also if in fact it's still oval ..... maybe draws explain better what i mean:

There is no "magic" inside the lens that can correct the fast axis, is just that the lenses are matched for "correct" in different degrees he light that pass from the center and from the external, so it become a bit more "linearized", as you can see in the first example (sorry, very schematics and a bit emphasized, just for give the idea) ..... where instead, using a single lens, the two divergent axis becomes collimated almost as they are, giving the spot more "oval" .....

Also be careful, if you want to disassemble one of them, to mark the sense of the lenses ..... the first positive element have an internal curvature that is or identical, or in some cases a very little less than the face of the negative one that go placed on it, where the external curvature is a bit more accentuated ..... once, i cracked the negative one just cause i placed the positive reversed in the tube, and it pushed at the center of the negative one, instead that on the border as in the normal mounting sense (the negative one is very thin in the center)

 

[LarryDFW]

Re: 445nm A130 Lens Comparisons!

HIMNL9;

Very nice explanation of the triplet differences on the fast & slow axis.

Unfortunately, the lens losses are triple for identical quality AR coatings.

I have found that a slight defocus seems to circularize the beam with my lens assembly & aperture.

LarryDFW

 

[jayrob]

Re: 445nm A130 Lens Comparisons!

Do you mean exchange the main (first) lens with the 405 one ? ..... if so, i'm sorry to say you that this probably don't work (and can end in the destruction of the negative lens of the triplet, too)

Those lenses in the triplets are built with specific curvatures, and focal lenghts ..... changing one of them, or also just the distance between them, just make the things worse ..... they are matched for correct the lateral deformation in the lens assemblies, mainly for photographic use, and is for this reason that the dot appear more "round", also if in fact it's still oval ..... maybe draws explain better what i mean:

There is no "magic" inside the lens that can correct the fast axis, is just that the lenses are matched for "correct" in different degrees he light that pass from the center and from the external, so it become a bit more "linearized", as you can see in the first example (sorry, very schematics and a bit emphasized, just for give the idea) ..... where instead, using a single lens, the two divergent axis becomes collimated almost as they are, giving the spot more "oval" .....

Also be careful, if you want to disassemble one of them, to mark the sense of the lenses ..... the first positive element have an internal curvature that is or identical, or in some cases a very little less than the face of the negative one that go placed on it, where the external curvature is a bit more accentuated ..... once, i cracked the negative one just cause i placed the positive reversed in the tube, and it pushed at the center of the negative one, instead that on the border as in the normal mounting sense (the negative one is very thin in the center)

Well it was a nice dream...

For sure the 405-G-1 is the most power with the 445's. And it's got a decent beam and dot as well.

I just had to be honest and give my true opinion that I liked the looks of the AixiZ 405 lens better. But at 15% less power is the draw back...

 

[New_Reverie]

Re: 445nm A130 Lens Comparisons!

Hard to complain about that 15% when you are still breaking .5W without a sweat.

 

[LASER66]

Re: 445nm A130 Lens Comparisons!

it's amazing that once we were discussing the advantages of the 405-G-1 over the 405-G-2 in a few mW's at 405nm, say at 500mW, way below the differentiation of our meters. Going for "Max throttle" of a diode, was the whole idea of going to the G series glass. Now 75mW of blue may be discarded like the 26% increase from Axiz acrylic to 405-G-1 was nothing. It is amazing what blue light will do to our brains!

Don't flame me, as I know many require a clean, collimated beam. Hey , that's why I send a small package to Jayrob yesterday. (let us know)
PS hit my REP button so I can launch above a rating of Zero.

 

[LASER66]

Re: 445nm A130 Lens Comparisons!

One thing that I neglected to mention last night pertains to the thermopile and the "G" lenses with this diode. At first, I noticed that the output seemed to fluctuate. I worried about that. I checked all the connections and solder joints. Everything was fine, so I did the measurement again.

This time I noticed that with the laser "focused" at the distance of the thermopile, that it was smoking the coating on the thermopile! The smoke was reflecting/blocking the beam :tinfoil:. This is usually easily avoided by defocusing the beam somewhat. However, with this diode and the "G" lenses, the "spot" elongates VERY quickly with defocusing. It is very easy to loose some of the light to the sides of the thermopile housing.

So, be mindful of your focus with this combination when measuring the output.

Peace,
dave

P.S. @ Jayrob -- I sent my comparison info to Will

Dave:

what head is on your 365? I would think it was rated for many watts??
too bad about the frying of the head surface.

Will

 

[kevinmassey]

Re: 445nm A130 Lens Comparisons!

Well it's so much more noticable with blue light. With violet you couldn't see the "wings" near as well.

 

[LASER66]

Re: 445nm A130 Lens Comparisons!

It will be nice to see how my AR coated Acrylic (ebay LASERS4U) will do against the un-coated AixiZ of the same design. Not that anyone will ultimately pick an acrylic, but it will be interesting to see the results of the Single Layer MgF2 coating. As an example to see an increase in Jayrob's power of 293mW for Aixiz acrylic.
Not a sales post!

Many are commenting about the coating differences...
If Red or B coated, a lens will only perform about 5% less than the same lens coated for blue, or A coating. The 14% difference in AiXiZ glass (red) vs AixiZ 405 glass must be more than a coating issue. I suspect it is not the same 3 element design, although some part is accounted for by coatings.
per JayRob...
AixiZ glass: 272mW, AixiZ 405 glass: 315mW at 445nm

 

[jayrob]

Re: 445nm A130 Lens Comparisons!

15% is a huge difference, but I have a feeling it is due to just the coating...

This is just based on the output of the beam and dot pattern.

But also, I have seen huge differences in other lenses that I know are the exact same lens, but with a different coating.

For instance, if you tried to use a normal AixiZ glass lens with blu-ray instead of red, it will be a huge difference...

Anyway Will, I got your package and I will be testing these lenses. But what is that large lens in the large nut?

I want to get a tap so that I can make a module for it to thread into. Do you know the thread size?

Please tell me more about this lens!

 

[RA_pierce]

Re: 445nm A130 Lens Comparisons!

Has anyone considered using two 405-G-1/Hi-power lens mounted together in the same housing?
Perhaps some of the splash can be reduced with better transmission than the Aixiz 405.

 

[daguin]

Re: 445nm A130 Lens Comparisons!

Dave:

what head is on your 365? I would think it was rated for many watts??
too bad about the frying of the head surface.

Will

It is a 36-0001. It is rated for 10W. However, the ratings are with the beam covering the whole thermopile. They are not designed to have "focused" laser light on them. I did not intentionally have it focused at the distance to the thermopile. That was unintended. The main info to take away from that is that the beam spreads out very fast. One cannot just give the lens a twist, and hope that it will all still be on the thermopile. One must check it visually

I have both 4-inch and 8-inch thermopiles here if I need to spread the beam even more

Peace,
dave

 

[kevinmassey]

Re: 445nm A130 Lens Comparisons!

Has anyone considered using two 405-G-1/Hi-power lens mounted together in the same housing?
Perhaps some of the splash can be reduced with better transmission than the Aixiz 405.

Do you really want to pay ~80$ for the 2 lenses, and lens assembly just to get slightly better results?

 

[jayrob]

Re: 445nm A130 Lens Comparisons!

Here's my new sleeve/retainer design to experiment with...

Just for this multimode diode:

I have to get to the Post Office right now, but will test it when I get back...

It's the exact same assembly as my normal 405-G-1 assembly, except for the sleeve/retainer has a small hole at one end instead of being drilled straight through...

We shall see!

(starting with a small hole, and can enlarge it if needed)

 

[RA_pierce]

Re: 445nm A130 Lens Comparisons!

Do you really want to pay ~80$ for the 2 lenses, and lens assembly just to get slightly better results?

I already have 2 lenses on hand. I might experiment with this when my diodes arrive unless someone who knows a bit about these lenses says it's not a worthwhile idea.

A single lens assembly already costs around $60. $20 more isn't a big deal to me.
We are only paying $50 for a 1W diode anyway.

 

[kevinmassey]

Re: 445nm A130 Lens Comparisons!

Ah! I thought that hole in the sleeve looked smaller than normal. Well I hope you get good results! I might have to get one of these just to switch out for burning.
Edit:

We are only paying $50 for a 1W diode anyway.

That's a good point.

 

[LASER66]

Re: 445nm A130 Lens Comparisons!

Just wondering ..... there's no way for know who produce the "aixiz 405nm glass lenses" ?

If only there was a way for get the same AR coating on the triplet in the aixiz one ..... with the natural distortion correction of a triplet scheme, it can be simply wonderful .....

Just dreaming .....



EDIT: BTW, some of the "artifacts / scattering" in the image, can be due from the lens edges reflections / refractions ..... i had some times ago some improvements, against them, painting the external edges and rims of the few lenses that i had here for test, with a permanent marker with very black ink ..... maybe this can help also in this case ? ..... just an idea

@HIMNL9...
I don't think there is much to the coatings. Being a low cost assembly (AixiZ 405glass) I would think it's maybe a multilayer A coating.

Let's get technical- OK to note color of coating, measure outputs, etc, However...

The true test is to do the following:
set up a test bed with whatever laser and whatever power.
Introduce a "test" lens
have that collimated beam shine a short distance onto the back surface of the tests lens.
measure the incoming beam (module/ pointer output).
measure the REFLECTED beam (back towards the module). Best if reflection is close to perpendicular to back (flatter) lens surface.
Calculate the percentage reflected. That will give a good indication of the coating.
Compare with uncoated, other coating, KNOWN Coating CHARTS etc.
Plot and compare between members.

Will
REP points accepted (sorry I have to beg, but I'm at a zero)