Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

Laser dot not perfect even with brand new lens

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
Hello,

I've been having issues with my 1W blue gatling style laser for a while now and I'm not sure how to fix it. After I was not able to completely clean the old lens I purchased a brand new three layer lens for it.
While the dot is much better now than it was with the old lens, there are still two areas around the dot where it is not perfect. Since I don't really know how to explain it, here is a picture:


It is a bit difficult to see on the picture because of the bright dot but in reality those areas are much more noticeable. Does anyone know what could be causing this? Since I already replaced the lens this must be caused by something else.

Thanks!
 
Last edited:

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
13,221
Likes
1,732
Points
113
Gattling lasers are among the cheapest crap lasers you can get. I hope you didn't pay too much for it. The laser diode is a multi-mode diode if it is actually 1 watt. That means you will never get a good Gaussian beam out of it. If you are having new issues with it, it could be debris burn onto the diode's window. Often it can't be removed, but if you can see it on the window and take a cotton swab with 99% isoproply alcohol and carefully try to clean it off. If it won't come off, just stop and live with it until the diode dies. In the future, keep your laser wrapped up and out of the air when dust and dirt can settle on it.
 

Encap

Well-known member
Joined
May 14, 2011
Messages
4,577
Likes
1,395
Points
113
Did you try the lens both ways--are you sure it is installed correctly?

Post a photo of the front of the laser where the lens is.

In case you didn't know --none of the multi mode 445nm blue lasers has a round (Gaussian) beam and dot output--they all produce a rectangular dot.

See: https://laserpointerforums.com/f65/there-something-wrong-my-beam-spot-59400.html

There are many other threads with examples--use the LPF Custom Search at bottom of page to find them

PS Please do a Welcome post in the Welcome sub-forum telling something about yourself and put your location in your profile. You will get a better response form members.
 
Last edited:

RB astro

Super Moderator
Staff member
Joined
Apr 6, 2014
Messages
2,453
Likes
1,312
Points
113
Chris, also, forum rules state that images should be 800 pixels wide.
Please resize your image/s since the one you posted is over 4100 pixels wide..

RB
 

ZRaffleticket

Well-known member
Joined
Feb 4, 2010
Messages
2,961
Likes
555
Points
113
Those artifacts to the sides of the spot that you circled are due to the lens. Not much you can do other than masking it someway, which won't be easy in the gatling host. Lens isn't defective, the beam is just too big and clips the side of the lens and makes this pattern.

I'm not sure if a G lens fixes this as I don't have one handy, but it definitely is the case for 3 element lenses as seen below

 
Last edited:

Mosc007

Active member
Joined
Feb 2, 2012
Messages
517
Likes
145
Points
43
A G2 Lens fixes the side spatulation but then you get a rectangular Block next to the main spot. Reflection from the front of the diode mount. Not sure which is worse.

We need new lenses for modern diodes.
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
13,221
Likes
1,732
Points
113
Do you know which diode this thing has in it? I don't. If it is a 405nm or 445nm, I wouldn't think the rectangular artifact would be an issue. Maybe if it is a MM 405nm.
 

Mosc007

Active member
Joined
Feb 2, 2012
Messages
517
Likes
145
Points
43
Do you know which diode this thing has in it? I don't. If it is a 405nm or 445nm, I wouldn't think the rectangular artifact would be an issue. Maybe if it is a MM 405nm.

No I don't know which diode. But it seems all the Multimode diodes have the same issue. I know enough about the spatulation wings on the side. And when I have seen that with a diode using a G2 lens removes them but always leaves the Rectangular box.

Of course this could be a different problem. But it looks very familiar.

I just use 2 or 3 Ellement glass now days. The Bright rectangular box frm a G2 is worse than this problem.
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
13,221
Likes
1,732
Points
113
I agree with that. I hate the rectangular artifact more than any splash or other aberrations from different lenses. I just have not seen it with the M140, NDB7875 or any of the other MM 445nm diodes.
 
Last edited:

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
Gattling lasers are among the cheapest crap lasers you can get. I hope you didn't pay too much for it. The laser diode is a multi-mode diode if it is actually 1 watt. That means you will never get a good Gaussian beam out of it. If you are having new issues with it, it could be debris burn onto the diode's window. Often it can't be removed, but if you can see it on the window and take a cotton swab with 99% isoproply alcohol and carefully try to clean it off. If it won't come off, just stop and live with it until the diode dies. In the future, keep your laser wrapped up and out of the air when dust and dirt can settle on it.
I paid about 50$ for it + 10$ for 6 batteries and a simple charger + EU adapter + another 6$ for a three layer glass lens. I could have gotten it a bit cheaper by buying it with everything included in a case but I decided to buy every part separately to increase the chance that it goes through customs.

For some reason I already knew that this was going to be one of the first answers but come on, it's not THAT bad considering the output power and the fact that it is a solid metal build. It certainly isn't high quality but it's also no cheap plastic crap. I've had it for quite a while now and so far it is working just fine (despite the problem I described in this thread).
 
Last edited:

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
Did you try the lens both ways--are you sure it is installed correctly?

Post a photo of the front of the laser where the lens is.

In case you didn't know --none of the multi mode 445nm blue lasers has a round (Gaussian) beam and dot output--they all produce a rectangular dot.

See: https://laserpointerforums.com/f65/there-something-wrong-my-beam-spot-59400.html

There are many other threads with examples--use the LPF Custom Search at bottom of page to find them

PS Please do a Welcome post in the Welcome sub-forum telling something about yourself and put your location in your profile. You will get a better response form members.
Yes, I am pretty sure that I installed it correctly because I tested it both ways.
I also know the actual shape of the diode output because I had it disassembled a few times before. In my case the shape is even worse and has some imperfections on one side as you can see here:


However, I am not sure why that is or how to fix it (if it is even possible).
I think that it might be because of this small metal thing that you can see here on the left when looking at the diode but on the other hand I am quite sure that I've also seen it on other diodes so it's probably normal:


As requested, here is also a picture of the front of the laser:


Here is also a picture of the "inside" where I screwed in the lens:
 
Last edited:

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
A G2 Lens fixes the side spatulation but then you get a rectangular Block next to the main spot. Reflection from the front of the diode mount. Not sure which is worse.

We need new lenses for modern diodes.
I actually did buy a G2 lens before but it was defective so I was never really able to test if it is any better than a three layer lens.
 

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
Do you know which diode this thing has in it? I don't. If it is a 405nm or 445nm, I wouldn't think the rectangular artifact would be an issue. Maybe if it is a MM 405nm.
It certainly is a 445nm diode. I do also have a 405nm laser pointer and it is very easy to tell the difference.
 

WizardG

Active member
LPF Site Supporter
Joined
May 9, 2011
Messages
639
Likes
243
Points
43
We need new lenses for modern diodes.
I'm intrigued by the idea of using silicone 'jelly' lenses. They would let us adjust the collimation of the fast and slow axis separately for, theoretically, as ideal a beam profile as possible with just a single lens. They can certainly handle several watts of optical power with no problem but you can't put an AR coating on them so losses would be much higher. Sigh, no free lunch.
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
13,221
Likes
1,732
Points
113
Though the 405nm and 445nm laser are easly to differentiate in person, from photos it is not so easy. Your 445nm looks more like a 405nm in your photo. That host is anything but a solid piece of aluminum. It is hollow tubes with a small brass disc in the center for a heat sink. Also, you don't need to multi-post to answer questions. Click on the "mulitquote" icon at the bottom right of each post you wish to quote and answer, but click on "quote" for the last one. Then you will have them all show up in one post and you can answer them all there.

Also, the lens you bought is a three element lens. Not three layers. It has three separate lenses in it.
 
Last edited:

Chris32

New member
Joined
Jun 12, 2018
Messages
8
Likes
2
Points
0
Though the 405nm and 445nm laser are easly to differentiate in person, from photos it is not so easy. Your 445nm looks more like a 405nm in your photo. That host is anything but a solid piece of aluminum. It is hollow tubes with a small brass disc in the center for a heat sink. Also, you don't need to multi-post to answer questions. Click on the "mulitquote" icon at the bottom right of each post you wish to quote and answer, but click on "quote" for the last one. Then you will have them all show up in one post and you can answer them all there.

Also, the lens you bought is a three element lens. Not three layers. It has three separate lenses in it.
Cool, but how does any of this help me? Ranting about the quality of my laser or my obvious lack of knowledge when it comes to lenses does not help me regarding my question. I am a software developer, not a laser/optics specialist. I never called the host a solid piece of aluminum, it is very obviously hollow and assembled out of different pieces and some of those pieces might be hollow as well. All I was saying is that the laser is made from metal and doesn't easily fall apart. No matter what question I have and what forum I post it in, people always start ranting about completely irrelevant things instead of answering the actual question. Why is that?

You probably missunderstood me regarding the wavelength of the laser. I said "it is very easy to tell the difference" to prove to you that it is a 445nm laser, not to hate on you for not being able to see it on the picture.

By the way, I did see the multiquote function but I already had most of my answers posted at that time so I decided to keep those posts like they are and use multiquote the next time instead.
 
Last edited:




Top