FS: Hi-Power AR Lens Assy- 25-30% Inc. vs. Aixiz

[LarryDFW]

This was posted on the question of seeing the "splash" with BluRay diodes...
thru various lenses:

I will say this; you have to have it perfectly focused on a nearby surface to see the rectangle. Once you project it more than a meter away the rectangle is no longer visible...
__________________
Traveller

This corresponds with my observations and photos I took @ 14 feet.

LarryDFW

 

[millirad]

I had to try the 6X with the DIY driver at 122ma. It's alive. The beam profile is noticably brighter with the AR glass lens vs the acrylic lens. I don't have a thermopile/LPM but a wild guess as to beam strength at the moment would be about 100mw, because the Aixis module is only getting barely warm after 40 seconds on. With the AR glass lens the beam shows up slightly in the dark. With the acrylic lens the beam is all but non-existent. Will probably wait for the flex-drive before taking it to 180ma, then the beam should be pronounced, and a burner. I'm more into beam visibility over the burning capabilties though. I'm just congratulating myself for having the cojones to risk doing it with the diy driver. ;-)

 

[Traveller]

This corresponds with my observations and photos I took @ 14 feet.

Larry,

I was of course talking about the projection from the AixiZ acrylic. The projection from any of the high NA lenses is easily visible from 5M away...

 

[LarryDFW]

Traveler;

I will say I did see quite a bit of splash...
on one of my customer's laser with the Hi-Power lens.

Upon further investigation, I noticed a grainy pattern when defocused to a larger round beam.

After a careful ultrasonic cleaning of the Hi-Power lens, the splash & grainy pattern remained.

Only after cleaning the glass window of the 405nm diode, did the splash and grainy pattern disappear @ 14 feet.

Maybe, any film on the diode lens accentuates the splash projection.

Has anybody else noticed any correlation ?

LarryDFW

 

[millirad]

I had the sweetest, tightest beam with a very clean profile using the red LD from my GGW sled with the AR lens. This was running at 160ma with the DDL driver, but the lead popped off of the positive terminal and so I shorted the cap and reattached it, but the LD blinked on and off. That intermittent connection on the positive terminal killed the red LD. I need more red LD's and I need the miniature slide on solder connectors for the LD's ;-) All that happened after hacksawing the red LD out of the tiny sled mount and enjoying the beam for quite awhile.

 

[Traveller]

Only after cleaning the glass window of the 405nm diode, did the splash and grainy pattern disappear @ 14 feet.

Maybe... but we're talking about two different 6X lasers from two different builders (one being Igor, who is known for his meticulous assemblies).

On the other hand, I've read cases where some builders use Windex to clean their diode windows... What do you use to clean them, Larry?

Last but not least, have a look at this thread I started. Did your customer's "splash" look like mine?

 

[LarryDFW]

Traveller;

I have talked at length to the lens coating specialist at the factory, where the lenses are manufactured.
We talked about several techniques to clean the coated lenses.

I use 99% IPA (Isopropyl Alcohol with no water).

I use a couple of techniques for cleaning:

1. For the Hi-Power lens assemblies, I use an ultrasonic cleaner, followed by a microfiber cloth.

2. For the diode window, I use the microfiber cloth wet with IPA.
Then I use a dry microfiber cloth.

The laser I cleaned was a good example, but the customer was flying to another city
in an hour to use the laser. Due to the time frame, I did not have time for beam photos.

The splash I observed at 2 ft., was the rectangular pattern like that in your photos.

LarryDFW

P.S. I am wondering how the diode window got the film on it in the first place, since it is protected by the lens assembly.

 

[Traveller]

I am wondering how the diode window got the film on it in the first place...

Thx for the cleaning tips!

Did you build the laser for said "customer"?

 

[srjacob]

Does anyone have any idea if one of the lenses will fit in an Igor Blu-Ray?

 

[Traveller]

Does anyone have any idea if one of the lenses will fit in an Igor Blu-Ray?

Yes, the lens assembly is in an AixiZ assembly. Hence, unscrew the existng lens assembly, screw in the hi-powered assembly

Just don't tell Igor you actually allowed dust to enter into his vacuum-sealed module... (j/k) :crackup:

 

[LarryDFW]

Traveller;

I only have one question ?

Does Igor use springs between the diode window and the lens assembly ?

If he does, then all the cleaning will not help (due to the spring scraping).

I am working on a new system which will eliminate the spring completely.

Stay Tuned to this thread.

Larry DFW

P.S. The laser that developed the splash from the diode window film...
was cleaned with ultrasonics before assembly.

 

[srjacob]

Igor uses a spring between the module and the lens. However, if you rotate the lens much, the spring will weaken and as your defocus the lens, it gets wobbly in the mount. I don't think that Igor uses a vacuum sealed housing, because when I got my 6x from him, there was dirt (or fingerprints) on the diode window. I cleaned it off and the beam looked much better. I am having problems with his acrylic lens and am eager to get rid of it for a glass lens.

I think Igor got a little sloppy in that last batch that went out.

Igor found the shortest wl 6x diode he had and put it in a laser for me, and I am grateful for that. The diode runs at around 402 nm (yes, I have a spectro to measure it) and it serves my needs fine. However, I am concerned with Igor as a supplier. I believe he greatly overextended himself with the lasers even before he ran into trouble with his business. I think he has far worse problems than he originally thought, and I have not heard from him for several months. I'm the one that gave him the advice that at least helped him get his tax situation cleaned up.

I use the laser as a UV illuminator, and typically will defocus the beam to get as large a spot as possible.

However, I am still in a quandary as to whos lens to get. I am concerned that Larry uses epoxy because I tend to keep the laser on for as much as 1/2 hour, and it gets fairly warm.

If Larry has a new way of mounting the lens that doesn't use epoxy and still gives me a good, clean beam, I would be interested in that. Right now with the acrylic lens, diffraction rings are driving me batty.

Steve

 

[LarryDFW]

Steve;

I have complete confidence in the Hi-Temp epoxy mounting system. The manufacturer rates it for usage @ 250° F.

I have used it for two years previously to mount 3 watt Cree UV LED's directly to aluminum heat sinks. Out of over three hundred 3 Watt devices running at hot temps, I have not seen even one bond failure. These UV light devices run @ 180° F continuously.

If you prefer, I can mount the lens with the original threaded retainer on the end of the lens assembly.

Just let me know which method you prefer.

I have used this UV laser for prolonged periods (15 to 30 min.) for some work to accelerate chemical compounds:

It has a 803 LD operating @ 125ma by a driver I designed with Static and OverVoltage protection.
Hi-Power Glass lens of course.
Front plate of aluminum for heat-sinking
It is powered by two #18650 2400 mah Sony lithium-ion rechargables for long operating hours.
It will defocus to a 12" x 10" beam @ ~ 4 feet.

Larry DFW

 

[Traveller]

...all the cleaning will not help (due to the spring scraping) ... The laser that developed the splash from the diode window film...

Assuming the spring-ends are curved "inwards" - which should always be the case for un-modded springs (insert grain-of-salt here), then grinding from the two metallic surfaces should hopefully be minimal and only noticeable over long periods of use... :thinking:

But anyways, a non-spring solution would be certainly everyone's best bet. I think Jay's mentioned Teflon tape as an alternative.

As for the diode-window-film... like I said, I find it really hard to believe that both Igor and Dave would use the same cleaning product (that consequently leaves a film / residue). I'd like to ask them what they use (if anything), but both of them are, ah, "busy" atm... :cryyy:

Maybe this film exists upon production of the original diode; that or everyone's using Windex... If you review the first few pages of Jay's lens thread, you'll see that a few others have the same "splash"... meaning there's a whole lot of film-coated diodes out there...

I have IPA, I have microfiber cloths, but I'm too scared to mess with the diode window. Igor informed me that he managed to "dislodge" a window while cleaning it... now said diode is a candidate for stress-testing but that's about it. I don't want to have to send my laser(s) back because I killed a window, so I'm going to live with the rectangles for now... .

I'd love to see someone more "qualified" (including yourself, Larry) prove the theory once and for all. With proof, I mean before / after images. Maybe the next time you come across such a filmy diode window... please document it, thanks

p.s. Last but not least, here's a macro of Dave's 6X. You can even see a few dust particles (proof of focus) but no film. Not that there's any guarantee that such a film could be captured by a lens...

http://flickr.com/gp/trave11er/0WfFV2

 

[Traveller]

there was dirt (or fingerprints) on the diode window. I cleaned it off and the beam looked much better. I am having problems with his acrylic lens and am eager to get rid of it for a glass lens ... Right now with the acrylic lens, diffraction rings are driving me batty.

Could you possibly eleborate on the pattern you saw due to this fingerprint or whatever? As for not being a lover of acrylic... ditto!!!

 

[LarryDFW]

Traveller;

I think the diode window "dirty film" just makes the splash more noticeable.

The only method to check this idea, is beam shots before and after cleaning the diode window.

The laser I noticed the "splash enhancement" on, just appeared to have a dirty lens assembly. I changed out the lens assembly with several I had just ultrasonically cleaned, and still had the more visible splash.

Only after cleaning the diode window, did the splash become less apparent.

LarryDFW