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



What type of artifact is this?




Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,605
Points
113
It looks to me like spherical aberration and/or standard interference pattern inherent of coherent light.
 

RedCowboy

Well-known member
Joined
Jul 10, 2015
Messages
8,216
Points
113
The best thing to do is try another lens and see what you get, that way you can rule in/out the diode/diode window.

---edit---

Besides that the artifact doesn't look like a big deal anyway, I mean who looks at a half watt 405nm spot that close anyway ???
Do you even notice it during normal operation ?

---edit---

Is that spot focused tight or unfocused?

How about giving your lens barrel a little push in the modules threads and see how much thread slack you have, it might just be pressed to one side or the other and with your lens barrel shortened the amount of misalignment in the thread slack may be more than normal, this may be simple lens misalignment due to thread slack and a shortened barrel.

Try using a stiff spring.
 
Last edited:

carulli2

Member
Joined
Jun 27, 2011
Messages
79
Points
8
The best thing to do is try another lens and see what you get, that way you can rule in/out the diode/diode window.

---edit---

Besides that the artifact doesn't look like a big deal anyway, I mean who looks at a half watt 405nm spot that close anyway ???
Do you even notice it during normal operation ?

---edit---

Is that spot focused tight or unfocused?

How about giving your lens barrel a little push in the modules threads and see how much thread slack you have, it might just be pressed to one side or the other and with your lens barrel shortened the amount of misalignment in the thread slack may be more than normal, this may be simple lens misalignment due to thread slack and a shortened barrel.

Try using a stiff spring.
The spot was focused. I think it is a slight misalignment of the lens due to the unique design of the sanwu pocket series. I will try and stiffen everything up with some Teflon tape.

Edit: you were right. It was just misaligned due to loose threads.
 
Last edited:




Top