445nm Lens Comparisons!

Re: 445nm A130 Lens Comparisons!

Pontiacg5 said:

Has anyone tried painting the edges of the lenses and the sleeve yet? I know I had a pulsar that I widened the aperture on and it started throwing a wierd ring around the dot. I painted the bare brass that was exposed from opening the hole and the ring disappeared.

Click to expand...

I've tried blackening the inside of the sleeve/retainer before:
http://laserpointerforums.com/f64/f...-31-increase-vs-aixiz-22497-4.html#post505071

... but not the edge of the optic.

I'll definitely experiment with that and report back in a day or so...

Re: 445nm A130 Lens Comparisons!

Pontiacg5 said:

Has anyone tried painting the edges of the lenses and the sleeve yet? I know I had a pulsar that I widened the aperture on and it started throwing a wierd ring around the dot. I painted the bare brass that was exposed from opening the hole and the ring disappeared.

Click to expand...

Yes, for this i suggested to try this too ..... in some cases, with my lenses, it took care of scattering and dispersions (in some cases more, in some cases less, it probably depend about how the lenses edges are "smooth" or "sanded" probably)

Re: 445nm A130 Lens Comparisons!

i just had the chance to do a few first tests on my 445nm (almost typed 405.. too used to it!) diode - thank you a lot, dave!
i am pretty impressed on the aixiz 3-element-lens too. the dot seemed small, at several ten meters. flying setup, so no numbers or pics yet.

as long as the diode wasnt pushed in an aixiz housing, i played with some cylindrical lenses as well - a tiny sub-mm fibercore, an approx 1mm core, bot plastics, and an approx 5mm diameter glass cyl-lens. the fibers were of absolutely no help. the glass rod seemed slightly more promising. instead of a wide, narrow line (raw output) i got a halfway symmetrical, fat blob on my ceiling.
obviously, you need to move the cylindrical lens as close to the laserdie as the lens' focal length. the fibercores have a fl of a fraction of a mm, you cant bring them that close to the die without decanning.
the glass rod, on the other hand, is way too bulky. i hoped to install something in between the diode and the regular collimator..

i think i will build me a pointer next days, and experiment further on correction when i have another diode, any more material to play with..

the 445nm forum is quite flooded. shall i open a thread for dedicated fast-axis-correction? here? in 'optics'?

manuel

Re: 445nm A130 Lens Comparisons!

My guess would be here, and if later Dave wanted to move your thread to optics, he could do that. (my guess)

Or you can also post in this thread as well if you like. Since it is about lens comparisons...

Re: 445nm A130 Lens Comparisons!

I would try some simple masking on the laser diode window- just some tin/ aluminum foil to start. The objective would be to try to eliminate the rectangular shaped splash before it gets to the lens.
What about beam shots of the diodes, with no lenses. Let's see some of those shots.
Just one possible solution, but go to the source of the problem.
One should be able to mask the splash, and not loos much power at all. Remember, the 405-G-1 and 405-G-2 have an NA of 0.6

Re: 445nm A130 Lens Comparisons!

This method that I tried did work very well to mask the splash Will...



Dave verified my findings. See his post here:
http://laserpointerforums.com/f65/445nm-a130-lens-comparisons-51456-8.html#post716994

And I must say, that although the 405-G-1 does work well with this new 445 diode. And gives the most power too, I still like the AixiZ 405 lens better because it 'clips' the diode 'line' shorter. And gives it more of a 'dot look'...

405-G-1 is still a good choice though...

Still waiting for some other possible options. I know there are a few trying cylinder lenses...

Here's a beam shot with AixiZ 405 glass lens in case you missed it:


Custom Focus Knob option for AixiZ 405 glass lens:
http://laserpointerforums.com/f64/fs-445-custom-focus-knob-aixiz-glass-lenses-51727.html

Re: 445nm A130 Lens Comparisons!

I was only commenting so that others could try to get Max power and reduce some side splash with G Series Glass Lenses.
. Yes, I saw the posts, thanks. Yes, the 405AixiZ does give a rounder dot.

Re: 445nm A130 Lens Comparisons!

I'm not sure where I should post this, so I guess it goes here in the lens thread.

I've been experimenting with cylindrical lenses...
So far, no luck. I've managed to get the beam into a decent square rather than a rectangle, but the problem is that I can't use the short focal length lenses with the cylindrical mounted over the diode can.

I tried 3 different focal lengths but none of them gave me the results I wanted, so I won't bother providing the specs (unless someone wants to know).

Our best bet is to use a very short FL cylinder lens before the collimating lens or a long FL lens after the collimating lens (which sacrifices the ability to focus).
The easiest will be to go with the second option.

If you are going for a labby set-up, I would recommend using anamorphic prisms to correct the beam.
The cylindrical lens approach is a nightmare.

Re: 445nm A130 Lens Comparisons!

RA_pierce said:

I'm not sure where I should post this, so I guess it goes here in the lens thread.

I've been experimenting with cylindrical lenses...
So far, no luck. I've managed to get the beam into a decent square rather than a rectangle, but the problem is that I can't use the short focal length lenses with the cylindrical mounted over the diode can.

I tried 3 different focal lengths but none of them gave me the results I wanted, so I won't bother providing the specs (unless someone wants to know).

Our best bet is to use a very short FL cylinder lens before the collimating lens or a long FL lens after the collimating lens (which sacrifices the ability to focus).
The easiest will be to go with the second option.

If you are going for a labby set-up, I would recommend using anamorphic prisms to correct the beam.
The cylindrical lens approach is a nightmare.

Click to expand...

Thanks for the information and testing...

The more I read, the more I'm just happy with the AixiZ 405 lens... (405-G-1 is good too)

Re: 445nm A130 Lens Comparisons!

RA;

After talking with a optics specialist, I think the anamorphic prisms usually have higher losses. He told me that power loss would be ~20% with typical prisms.

I am still playing with cylindrical lenses after the aspherical.
I think it will give the most circular beam and power.

This is the Hi-Power aspherical lens set-up I got the best results & power with.
It has a steel aperture mounted on the lens assembly, right in front of the diode:



It minimizes the fast axis of the 445nm diode creating a slightly better beam pattern.

LarryDFW
445 "Direct-Drive" Member

Edit P.S. 7/10/10-Photolexicon has reported special AR coated prism sets with losses under 10%

Re: 445nm A130 Lens Comparisons!

Thanks RA and Larry for posting! what exactly are you testing as cylindrical lenses?

cheers,

manuel

Re: 445nm A130 Lens Comparisons!

daguin said:

Just for fun, I also tried the AixiZ 405 lens ... The spot is MUCH "rounder" with this lens...

Click to expand...

Hmm, this is starting to sound like Igor's search for the Holy grail of 405 lenses... .

A 405nm diode also looks "cleaner" behind an Aixiz lens than behind Jay's or Larry's HiPo lenses, but when viewed closely (read: behind a HQ camera lens...) the diode always produced the same exact shape, only in different intensities:



Jay, I seem to be way behind the 445nm scene, but if you can produce a "production" version of a properly-mounted Aixiz glass lens to work with your press-in Heatsinks, I'll buy one from you and do the very same test I did above with my W.I.P. 445nm JayGuin Lazor...

***EDIT***
I guess this is what I was aiming for, no?

jayrob said:

I have some full length thread lenses coming, so I may just offer a lens with the custom focus knob for $25 plus $3 dollars shipping. Or just the custom focus knob for $15 plus $2 dollars shipping...

Click to expand...

Re: 445nm A130 Lens Comparisons!

Larry:

My lenses were all positive focal length.
Now that I think of it... Could a negative short FL cylindrical be used to expand the slow-axis to match the fast-axis instead? Perhaps this would make it possible to mount the cylindrical over the diode and still be able to use the aspheric...

Lens 1: 2.2mm FL- I didn't really like this lens. The beam shape was very sloppy. Either this was a low quality glass lens or the dimensions made it unsuitable for this application (or both). The beam was rectangular with lots of splash and artifacts. This lens seemed to make the multi-mode "stripes" of the beam more pronounced.

Lens 2: 8.7mm FL- I liked this lens best. It gave me the best (square) beam of all three but could not be used with an aspheric, since the FL was too long.

Lens 3: 5.8mm FL- This lens worked about as well as lens 2, but with a more distorted beam, similar to lens 1.

My observations with cylindrical lens testing:
The raw output can be corrected using a cylindrical, but you can forget about doing this with an Aixiz module. The output after the cylindrical is difficult to collimate.
I think you are right, Larry, that a cylindrical after the aspheric will be the best option. Right now I can't afford to do any more testing.
Is your new aspheric assembly just a single element with a ring to block some of the splash or do you have a cylindrical in there too?

Re: 445nm A130 Lens Comparisons!

Traveller said:

Jay, I seem to be way behind the 445nm scene, but if you can produce a "production" version of a properly-mounted Aixiz glass lens to work with your press-in Heatsinks, I'll buy one from you and do the very same test I did above with my W.I.P. 445nm JayGuin Lazor...

***EDIT***
I guess this is what I was aiming for, no?

Click to expand...

The AixiZ 405 glass lens sticks out farther than most lenses...

So I made a custom Focus Knob to compensate for that, and give it a clean look.

I made it the same diameter as an AixiZ focus ring so that we can still use our silicone tail cap 'dust caps'.
http://laserpointerforums.com/f64/fs-445-custom-focus-knob-aixiz-glass-lenses-51727.html

Lenses on order from AixiZ...

Re: 445nm A130 Lens Comparisons!

RA_pierce said:

Larry:

Could a negative short FL cylindrical be used to expand the slow-axis to match the fast-axis instead? Perhaps this would make it possible to mount the cylindrical over the diode and still be able to use the aspheric...

Is your new aspheric assembly just a single element with a ring to block some of the splash or do you have a cylindrical in there too?

Click to expand...

A negative cylindrical could be used, but with both axis diverging @ 40°,
you could not use the short FL aspheric lens required for a narrow beam.

The lens assembly I am using is the Hi-Power like you have,
with an additional stainless aperture.

LarryDFW

Re: 445nm A130 Lens Comparisons!

bump

Peace,
dave