Beam problem

[UrbanTurban]

I finished my first 650nm SOC @ 300mA build yesterday, lasers are amazing!
so i am wondering is the beam supposed to look like this from around 6m? I can see interference patterns and a lot of random speckles

heres the same beam with less power

and also, i seem to have a scratch on my lens, is this what is causing it?

i can also notice a very big "cone" of light from the lens even when focused to infinity. Is this normal and am I losing a lot of power?

 

[Blord]

The lens is dirty. Try to clean it with Q-tips.

 

[aryntha]

May not be the lens. May be the diode window. And q-tips are probably not the best option if it is the diode window. You'll want something lint-free. I use something called PecPads that you can get at photography stores. Also, don't use 70% Isopropyl; try to use 99%, or if you can get it, methanol.

Rotate (focus) the lens. Do the patterns rotate with it? If so, then the dirt is on the lens. If they stay still, then it's on the diode window.

You have to be VERY careful when cleaning the diode window.. it's very easy to crack.

Note, you'll never get it perfect, but it should be a bit better than what shows in your photos. So try cleaning, first.

 

[UrbanTurban]

nope, cleaning didnt work
but is the diode window the small thin mirror surface on the diode? Then cleaning it should be very dangerous

 

[Blord]

If the diode has a window then it isn't a Short Open Can diode as you said in openingspost. A SOC has no window.

Cleaning the window of the can is possible. Use the same methode as aryntha describes. Just don't push too hard on the window.

 

[Benm]

Remove the lens, shoot the laser at a wall a post a picture of the result if you're incertain, we will be able to help you better that way.