Merged 445nm Pictures and Video Thread

[BShanahan14rulz]

Perhaps just a new way of building diodes that we have yet to understand. The new red LOC's do the same thing almost. If you up the current on those, the output drops. BUT! When you drop the current back down, the diode performance bounces back up with no degradation.
I'm just spouting info that was in the new LOC thread, haven't personally seen these.

 

[ossumguywill]

Yeah, but with the LOC thing they have a performance curve that looks to me like a thermistor inside the diode (EG designed to decrease output slowly). It's something different here methinks...

 

[qumefox]

Yeah, but with the LOC thing they have a performance curve that looks to me like a thermistor inside the diode (EG designed to decrease output slowly). It's something different here methinks...

It's not a thermistor in the new LOC's. Read that thread. If it was thermal, then the power would fall off as temperature rose even at the same drive current. But that's not happening. I think the cause with the new LOC's and these 445's are probably the same. The main difference it seems is where the effect happens. With those new LOC's, it was happening below the point of optical facet damage, so the power always came back 100%. The 445's start degrading below 2A, so 2.3A where the falloff starts is most certainly causing damage.

 

[kingdave2357]

I am waiting for a good foggy night to get some sick beam shots. They are pretty nice as is but with fog it would be amazing.

Lol, that was with rather thick fog, and it was pretty amazing. Only way to beat shots like that is to either have a stronger laser(over my >1W) or if you live by water or somthing were you get the super dense fog from time to time...

I should go find a swamp somewhere that gets really foggy and take some pics there...

 

[ossumguywill]

It's not a thermistor in the new LOC's. Read that thread. If it was thermal, then the power would fall off as temperature rose even at the same drive current. But that's not happening. I think the cause with the new LOC's and these 445's are probably the same. The main difference it seems is where the effect happens. With those new LOC's, it was happening below the point of optical facet damage, so the power always came back 100%. The 445's start degrading below 2A, so 2.3A where the falloff starts is most certainly causing damage.

The power in the new LOCs drops off slowly, not instantly like with these new 445s. So it can't be exactly the same IMO.

 

[qumefox]

The power in the new LOCs drops off slowly, not instantly like with these new 445s. So it can't be exactly the same IMO.

Why not? We are comparing a 1 watt 445 diode with a 200mw 650 after all. I see no reason why a similar protection method wouldn't behave a bit differently given the vast differences in the diodes. There are enough similarities in the behavior to lead me to believe it's probably a similar mechanism causing it.

 

[ossumguywill]

If you look at an I/P graph, the LOC makes a bell curve while the A130 makes a sawtooth.... I think that's enough to indicate a different mechanism, like a change-sensitive resistor versus a nanofuse or something.

 

[qumefox]

Where have you seen I/P graphs for this diode at this current? The only graphs I've seen stop at 2A and these diodes don't start falling off until 2.3A The only information i've seen on driving these at >2A is the video posted on this thread.

 

[ossumguywill]

No lol but it's not that hard to make one in your head, I'm not suggesting the existence of an actual graph, but it's pretty apparent that the 445 would make a sawtooth and we can see graphs that show the LOC making a bell curve.

 

[qumefox]

Just judging by the video, it's a steeper drop than those 'new LOC' diodes, but doesn't appear to be a sudden instant drop off. Without actual I/P graphs, we're just guessing though. I have a lab psu that will do constant current up to 3A. Maybe i'll sacrifice (if I can kill it anyway. lol) one of my 445's to make a graph at >2A I'm kind of wondering if the falloff only looks steeper because of the higher power of the diode. If it happens over the same current range, (roughly over a 300ma range from peak to off right for those 'new LOC's?) If it is over the same range, it's just the 2.3A ramp up before the falloff that makes the curve look sharp.

 

[DjHeadie]

and one of the dog vs peanut butter for good measure.

 

[yobresal]

Nice! what speed are you scanning? Those 2 colors look sweet together.

 

[DjHeadie]

Nice! what speed are you scanning? Those 2 colors look sweet together.

at about 120 rotations per minute! lols. its a modulated signal hitting a mirror having computer fan, just to spread the blue out for the pic, and to tickle my fancy.

btw i will have LOADS more pictures once this mini-beast is scanning.

still got the 3.7's with a charger around? havent been able to get my hand on one yet and havent seen that things gorgeous glow in quite some time!

 

[yobresal]

Here is my multimode 445nm laser
500mW CW/ 50mW pulsed/ & Photonic distruptor 500mW blasts with 250mW average.
http://img715.imageshack.us/img715/3233/mvi0560.mp4

 

[ossumguywill]

How did you do that? Flashlight driver or other?

 

[yobresal]

I don't know. I was sleep building and when I woke up I had this awesome laser next to my pillow. My soldering iron was still hot and I had burn marks all over my hands. Pretty crazy stuff eh?