weird PHR

[maxkillz]

I made a blu-ray late last night and it seems to be very weird. The dot is very dim and thin with dark spots yet it burns just as well as all the others I set at 100mA :-? is it in a kink or just very low wave length? it looks about as bright as a 5mW red :-/ the camera picks it up brighter and better than my eyes can

 

[FireMyLaser]

Interesting. Compare how it makes things fluorescence against a normal diode.
Does it fluorescence certain things that a normal diode can't?

 

[ElektroFreak]

Unfortunately, if the spot from a laser diode has dark spots or stripes in it it means the diode is shot. It may still lase, but it no doubt will have a short life. The output wavelength could also be affected, making your diode closer to a UV laser than visible violet.

 

[brtaman]

I made a blu-ray late last night and it seems to be very weird. The dot is very dim and thin with dark spots yet it burns just as well as all the others I set at 100mA :-? is it in a kink or just very low wave length? it looks about as bright as a 5mW red :-/ the camera picks it up brighter and better than my eyes can

Hey,

Do you see this dot and dark spots with the lens on? I have had these dark spots appear, while I thought it was the diode dying, it ended up being plastic from the aixiz lens nut which got chipped due to all the focus adjustments. It ended up getting baked onto the diode window. I managed to clean it off though using a solvent i had laying around (nitro or other dont remember) using a q-tip and force, just enough to scrape plastic off without damaging the diode window.

Here is a little trick:

1: Adjust focus of the blu-ray so that it projects a huge circle on the wall, in which the darkspots are clearly obvious.

2: Now start twisting the focus knob. If the dark spot moves, then there is some dust on the lens. If the spot doesn't move then it is most likely a contaminated window.

It is really hard to see if there is something on the window, at least it was in my case, had to use a magnifying glass and a lot of light...even then I could barely see that it was on the window. That minuscule piece of plastic produced quite a large distortion though, due to its proximity to the die.

 

[maxkillz]

could temp affect a diode like this? I noticed when it was very cold ( roughly 17F) it seemed weird now I checked inside and the dot seems fuller now at 60F but still very dim for the power, it still burns like crazy though just like my other blu-rays but they were all MUCH brighter than this one

 

[daguin]

could temp affect a diode like this? I noticed when it was very cold ( roughly 17F) it seemed weird now I checked inside and the dot seems fuller now at 60F but still very dim for the power, it still burns like crazy though just like my other blu-rays but they were all MUCH brighter than this one

Temperature WILL effect diodes. You may be right at a kink. Your diode may be going into and/or out of the kink as the output increases and/or decreases with temperature changes. Crank it down or crank it up, but get it away from that kink.

Peace,
dave

 

[maxkillz]

it's a fixed output Rkcstr driver, could I change it?

 

[daguin]

it's a fixed output Rkcstr driver, could I change it?

Darn! Bad luck. If the "spot" looks better at 60 degrees, always run it warm. Keep it out of that kink.

If your diode is closer to 400nm it will be less "visible" while still just as powerful. The only way to really tell is with an LPM.

Peace,
dave

 

[maxkillz]

looks like I won't be able to run it outside for the rest of winter :'(

did I just get a freak or do a lot of them do this?

 

[daguin]

looks like I won't be able to run it outside for the rest of winter  :'(

did I just get a freak or do a lot of them do this?

All of the PHR's do this (as well as some others). Each diode is a little different. The kinks come in at similar, but varying currents. Unfortunately, your fixed driver just happens to be at the current that THIS diode is in a kink at. That's why I wrote, "bad luck." If you put a different diode on it, it may turn out differently. You can still play with it outside, you just have to keep it in an inside pocket and don't let it cool down too much in between burns.

Peace,
dave

 

[maxkillz]

ah, maybe next time I should get adjustable current drivers so I can avoid this :-/

 

[john_lawson]

ryan sells a resister kit i have purchased some before you'll see them on the board  just add or remove a resister for a different value i dont have the actual value's? for this i just compare to another driver myself

if you want i can send you a few resister chips for free you just have to be skilled at soldering for this step  i have done it but i dont like it way too small for me