Having trouble with 6x10mm diode housing

[poseidon05]

I am new to building lasers and need help. I am trying to build a 505nm pointer. I got a 505nm35mw diode and a laserland 6x10mm focusable diode housing with plastic lens. The problem is that if I focus the beam down, there is a lot of artifacts around the dot (see pic). The smallest I can focus it to without much artifacting is about 1 inch diameter at 3 feet away. I've now noticed that the diode is a TO56 while the housing is made for TO18 diodes. Could that be the problem? Or is there something else that I'm missing?

 

[RedCowboy]

T0-18 or T0-56 are both 5.6mm diodes ( the width of the backing plate )

Try one of the copper modules HERE and choose a G2 lens for a tight beam in the near field and a G8 lens for your best far field beam..... Better yet get one of each and a 2EG ( two element AR coated for green or 450-600nm ) for general purpose.

You can also get a G8 lens HERE

 

[poseidon05]

T0-18 or T0-56 are both 5.6mm diodes ( the width of the backing plate )

Try one of the copper modules HERE and choose a G2 lens for a tight beam in the near field and a G8 lens for your best far field beam..... Better yet get one of each and a 2EG ( two element AR coated for green or 450-600nm ) for general purpose.

You can also get a G8 lens HERE

Those are too big since I'm trying to build it into a pen host.

 

[WizardG]

How did you press your diode into the housing? I had a 405 diode that looked like your picture. The diode wasn't sitting flush in the housing so the raw output was hitting the edge of the lens instead of the center.

 

[poseidon05]

yeah its flush

 

[Darktron]

Clean the optics?

 

[WizardG]

Clean the optics?

Worth a shot, but that really looks like misalignment of the optics to me.

 

[RedCowboy]

Yep, misalignment and a poor quality plastic lens.
If you look at those cheap modules the lens is simply pushed by a spring, so any deformation in the lip of the cap or even if the end of the spring isn't flat, will throw it off, plus those acrylic lenses are often garbage....... Try turning the spring around so the flattest end is against the lens ??

 

[poseidon05]

Yep, misalignment and a poor quality plastic lens.
If you look at those cheap modules the lens is simply pushed by a spring, so any deformation in the lip of the cap or even if the end of the spring isn't flat, will throw it off, plus those acrylic lenses are often garbage....... Try turning the spring around so the flattest end is against the lens ??

I've tried with the spring both ways, and without the spring, same result each time. I think the problem is that there's a long narrow tube between the diode and the lens, and the diode's output hits the walls of it before reaching the lens. But I've seen videos of this exact casing and the beam didn't have any artifacting for them, so it doesn't make sense.

 

[WizardG]

I've tried with the spring both ways, and without the spring, same result each time. I think the problem is that there's a long narrow tube between the diode and the lens, and the diode's output hits the walls of it before reaching the lens. But I've seen videos of this exact casing and the beam didn't have any artifacting for them, so it doesn't make sense.

OK, this picture, with the diode running. Turn the diode off and see if it's centered in the module. If it is then I'm gonna suggest trying a decent glass lens with a short focal length to capture the light before it spreads out enough to clip the edge of the 'tube' like that.