Help with DIY laser pointer

[khm2008]

Hey I'm trying to build my own laser pointer with the LM317T voltage reg driver circuit. I have it all built and working but the laser is very very very weak so weak that when in the dark it will only go a few CM if even that. I have a few differences to the diagram I was using first it says to use two 10ohm resistors in parallel to give 5ohms but I didn't have any 10ohm so I used four 22ohm resistors in parallel to give me 5.5ohms and I changed my pot from a 100ohm to a 470ohm to try and get more power to the diode but that didn't work. The only other difference I can see from the diagram on this site and the one I used it that my voltage reg connects to the cap and diode before the resistors and the pot but that shouldn't matter. Now for the last part the only thing I don't know much about is the laser diode itself as I striped it from a DVD burner.

I toke some voltage readings off the diode with the pot at full power I'm getting 1.9V and at the min I get 1.4V. I can't get a reading of the current with my multimeter, it only has one setting for amps to read up to 200mA DC.

Any help/advice you can give would be great
Thanks khm2008

 

[kilter]

Are you sure it is a DVD BURNER and not a DVD player?

 

[khm2008]

Now that you say that I'm not 100% percent sure as I striped about five drives from laptops and desktops I'll strip another drive now that is a burner and keep the rest of the diodes away from my work area while I'm doing it. Is there any way to check the diodes I have already taken out as I won't be able to know which one came from what drive?
Thank you for the reply

I just swapped out the laser for a new one that is from a burner and it is a small bit brighter but still nowhere near what I see in other peoples videos/pictures would I be better off putting the 100ohm pot in again instead of the 470ohm that is currently in it, can any body give me some voltages that I should be getting at different points and what voltage should be at the laser diode please so I can run some tests

I forgot to say in the first post that my driver circuit also has a extra 1N4001 diode between the power supply and the LM317T and the power supply I'm using is a 9V battery in case that makes a difference

 

[The Lightning Stalker]

It could be that you have a dual diode with both red and infrared diodes inside. Make sure it is actually
attached to the red one and not the infrared. That is particularly dangerous because what appears to
your eyes as a dim glow is intense invisible light that has the potential to burn your retinas.

I hope you're not doing any of this without laser safety glasses. Unfortunately, none of the cheap ones
work at 650-660nm even if they say they do. Also, most of the red ones don't block infrared, so you
should pick up a pair of those as well. Survival Laser sells some that are supposed to work well, but
you should get better ones if you can afford it, such as the ones AixiZ sells. The right ones will be a
blue color. Absolutely do not buy any from eBay or o-like. Those are guaranteed not to work.