Weird Effect around dot

[hakzaw1]

Just heard good newz-aixiz now has half-threads back in stock-I am picking up a supply Sunday at aixiz.

bad newz - the newest batch of full thread 400-450 glass may have a few with coating issues-

Chuck is doing pretty much all he can do about these IMHO=but please

you need to keep in mind two things- they are made in China(long way off) and Dr C is a busy dude with a lot of irons in his fire.
hope i have been helpful
solo mis dos centavos
hak

 

[Tech_Junkie]

I think its a dirty window also. My Arctic has the same artifacts, and you can see spots on the raw output. My Ehg build has the same set up, with no dirt, and no artifacts.

 

[DTR]

I have noticed when you turn the lens the splash does not move with would normally tell me that it is not the lens but the diode. So I tried a decanned 445 I got the same effect. So I don't think it has anything to do with the window. Now when I take the lens out keeping the same orientation of the laser I find the splash and the bars are both horizontal. Also if I screw the lens in much further than infinity the splash goes away. Could it be the light from the edges of the bar are not making it into the aperture and scattering off the metal nut?

 

[anselm]

You might have some q-tip fuzz (or similar) between diode and lens.

 

[hakzaw1]

Look at your diode window w/ a magnifying glass- i found that a tiny bit of my teflon tape had gotten on my window a melted there.

On another 445 build a bit of thermal paste from the Ca5io projector got on a window. not visible by the naked eye.

hope the has been helpful
hak

 

[RA_pierce]

I have noticed when you turn the lens the splash does not move with would normally tell me that it is not the lens but the diode. So I tried a decanned 445 I got the same effect. So I don't think it has anything to do with the window. Now when I take the lens out keeping the same orientation of the laser I find the splash and the bars are both horizontal. Also if I screw the lens in much further than infinity the splash goes away. Could it be the light from the edges of the bar are not making it into the aperture and scattering off the metal nut?

Yes.

The beam of these 445nm diodes is much more elongated than the profile of some other diodes. This artifact is also apparent on one of my 635nm diodes that outputs a narrow stripe much like the 445nm diodes at low power.

Because of the way the Aixiz lens is designed, some of the power gets lost, as we know. In this case, the edges of the beam are clipped by the narrow aperture and are splashed to the side of the beam.

As you turn the lens closer to the diode, more of the beam is able to enter the lens rather than get clipped by the sides so the artifacts disappear.

 

[oic0]

Ive never noticed it around mine but I never use it without goggles so maybe I miss it?

 

[Elektrotechniker]

Ive never noticed it around mine but I never use it without goggles so maybe I miss it?

There it is. To the right of the dot. A solution to this would be to make the aixiz focus rings more "closed"(smaller inner diameter) so that side light would not exit the module. I will try to do a modification on this. I used both clean and new diodes and lenses and got the effect again and again. Dunno what the hell is going on.

 

[danefex]

That is weird Silver..... I have this w/ all my 445s but not nearly as tight or presented as the 1st picture up there where it looks like a blue saturn (not the car). I always figured this was from the 2 little grooves that act as a screwdriver indent for focusing the Aixiz lens, as those indentations allow light to slightly leak offset from what would otherwise be a near perfect circle with the exception of the 445 being MM and producing a rectangle beam. DTR's picture shows what I'm used to but it is also very exxagerated from what I consider normal.

I am curious what fixes this for you, I'm sorry I don't have any better suggestions than what've been offered

 

[Elektrotechniker]

That is weird Silver..... I have this w/ all my 445s but not nearly as tight or presented as the 1st picture up there where it looks like a blue saturn (not the car). I always figured this was from the 2 little grooves that act as a screwdriver indent for focusing the Aixiz lens, as those indentations allow light to slightly leak offset from what would otherwise be a near perfect circle with the exception of the 445 being MM and producing a rectangle beam. DTR's picture shows what I'm used to but it is also very exxagerated from what I consider normal.

I am curious what fixes this for you, I'm sorry I don't have any better suggestions than what've been offered

What about thowe 2 little grooves? Are these the ones fault for the effect? Sorry but that's what I figured you meant :/

 

[RA_pierce]

As I explained above:

The beam of these 445nm diodes is much more elongated than the profile of some other diodes. This artifact is also apparent on one of my 635nm diodes that outputs a narrow stripe much like the 445nm diodes at low power.

Because of the way the Aixiz lens is designed, some of the power gets lost, as we know. In this case, the edges of the beam are clipped by the narrow aperture and are splashed to the side of the beam.

As you turn the lens closer to the diode, more of the beam is able to enter the lens rather than get clipped by the sides so the artifacts disappear.

@oic0: I can see it faintly in the picture you provided. The further away the surface is from the aperture, the more the splash spreads and becomes less apparent.
Some diodes make less splash, some make more. It really depends on the diode's beam profile.

@others: The "grooves" for the screwdriver do not affect the pattern of the splash. The artifacts should not be very noticeable unless you are looking for them. One way to reduce the splash is to use a small (<4mm dia.) aperture a few millimeters from the lens.

 

[danefex]

I don't think they're the direct cause of what your problem is Silver, no. I was just saying that I know those 2 little grooves let a fraction of light leak out of what is otherwise a circle, leaving a very dim slight 'rectangle bleed' though what would otherwise be the dot.

DTR's pic is a perfect example of what I'm explaining except as he says in his post, that picture is an overpronounced example of what we’re talking about.

Your picture from your first post is unusual and I wish I had a suggestion different from what everyone else has said & what you’ve tried. I think Daguins spot on about the diode though, because if you’ve already thoroughly cleaned your lenses alongside switching them up – it’s definitely the diode imo

 

[danefex]

As I explained above:

I'm sorry I didn't see this before as I just replied, I also agree with you :beer:

 

[dark racer]

what couses that other effect that nearly all lasers i've seen have . it's hard to explain when the light of the beam not the beam it self reflects of of something or get spread out over a larger surface . that light is not just a green glow but it always seems like bacteria or something moving around that make up the glow .

anyone knows why this is ? could be that i'm asking a dumb question but i basicly only know how that first laser in the 60's worked

 

[Cyparagon]

That question is answered almost every month. It's hard to know what to search for though, so I'll forgive you. :shhh:

Speckle pattern - Wikipedia, the free encyclopedia

 

[dark racer]

what do i search for then?