Rayfoss/Mitsubishi 638nm 300mW laser diode

[Fiddy]

^^oath!
here are some beam shots i posted in the other thread!

 

[Eudaimonium]

What does "Oath" mean?

Yeah I've seen your beamshots, and I can tell the beam profile of the red is really bad, it's clearly a line being emitted. Can you at least try to focus it into a square or something?

I'll be toying around with focusing, see what I can get with Acrylic and Glass lens from Aixiz, Cyparagon said there is no noticable difference in power transmission.

 

[Fiddy]

lol

1. fucking oath

Australian slang. Commonly used instead of the words "I'll say!" or "Damn straight".
"It's a bit cold outside."
"Fucking oath, it is."

yea it is, you can go square but its larger than the line...i should take some photos with different lenses and focusing

 

[Eudaimonium]

Oh, I'm not familiar with Australian slang, I do know what else a "Down under" means ....

Sorry.

Yeah, would you mind taking a beamshot or two with beam focused to square?
I'd love to see that!

 

[Fiddy]

hehe no worries...

random funny:

Guy: ever tried a aussie kiss?

Girl: no whats that?

Guy: its like a french kiss but down under

will get out and take some shots now!

 

[Eudaimonium]

Haha :crackup: good one! :beer:

I'll keep an eye out on this thread for few more minutes, then I'll be offline for few hours, trip back home and stuff.
No better way than to pass time at boring classes then looking at beamshots of new ground-breaking diodes.

 

[Fiddy]

Some quick shots


AR Coated Acrylic

Aixiz 3 Element Glass

650-G-1

 

[Benm]

The problem is that this prism drops 50% of the power. It's just for proof of concept. I have several coated prisms on their way from surplus shed.

I think you may want to use 2 prisms instead of one: More surfaces may seem to make things worse, but this doesnt have to be the case: When using two prisms, you hit them at a less shallow angle causing lower reflections.

Take a look at the diagram under technical specs here: Anamorphic Prism Pairs - Edmund Optics and compare the placement to the single prism.. quite a difference!

 

[Helios]

Anyone else find it weird these diodes peaked at only 500mW?! Didnt DTR break 1000mW at well under 1.8A? and lazereer and fiddy both exceeded 500mW by a good amount while still at lower currents.

 

[regalis]

It seems IMHO that nearly the half of them diodes are freaks..

 

[Cyparagon]

^^^Any way at all to make that work in a handheld?

The prism works great, But it requires the diode to be on a different axis than the output beam. For handheld builds, you might want to go with cylinder lenses.

I think you may want to use 2 prisms instead of one: More surfaces may seem to make things worse, but this doesnt have to be the case: When using two prisms, you hit them at a less shallow angle causing lower reflections.

At normal angle, I found ~14% loss. So if you use two, you're back up to ~30% loss, and you double the optics price. It works at normal angle fine, just with less magnification than at a shallow angle.

Anyone else find it weird these diodes peaked at only 500mW?! Didnt DTR break 1000mW at well under 1.8A? and lazereer and fiddy both exceeded 500mW by a good amount while still at lower currents.

From a cold start (heat sink at 60F), they do 10-20% more than when they warm up. If you add in the single-element lens (g1-series), that explains all the readings except DTRs. Either he's binned them, gotten lucky, or his meter is out of calibration. Or maybe all of our meters are out of calibration :tinfoil:

 

[daguin]

So I have a question.

current isn't killing them. But that doesn't mean that the current won't cut the life expectancy on them, does it?

Do we have any way to test that? (I thought someone had a rig for something like that)

There was a torturer testing rig someone had. I remember seeing a thread about it when the 445's first came out. It may be a member that is not active here anymore.:thinking:

It was IgorT.

He hasn't been around for some time

Peace,
dave

 

[Elektrotechniker]

We need to get him back :shhh:

 

[DTR]

Anyone else find it weird these diodes peaked at only 500mW?! Didnt DTR break 1000mW at well under 1.8A? and lazereer and fiddy both exceeded 500mW by a good amount while still at lower currents.

If you looked at the video it peaked over 1W for a few seconds but very quickly dropped to a little over 800mW and just sat there. I did build a host that I am doing a review on with these diodes last night. 975mA and it was running only 785mW.:undecided:

From a cold start (heat sink at 60F), they do 10-20% more than when they warm up. If you add in the single-element lens (g1-series), that explains all the readings except DTRs. Either he's binned them, gotten lucky, or his meter is out of calibration. Or maybe all of our meters are out of calibration :tinfoil:

It was definitely luck as I normally don't go around ripping the cans off super diodes for the fun of it.:crackup:

It is obvious at this point that these diodes do vary in efficiency. I have only kept 2 diodes out of 30 that I have received. There is the one that had the damaged diode window that I decanned and used for the experiments. And the one I built last night that was less than I expected.

The diode I tested gave 700mW @ 750mA which is not as good as the one lazeerer has that was giving 800mW @ 740mA but the one I built last night is only giving 785mW @ 975mA. So there are obvious differences in efficiency.

Regardless the one I built last night I took outside and it was the most amazing red beam I have ever seen.:eg: Also if you turn it so the the line is vertical with your line of sight it looks like it has very good divergence.:tinfoil:

 

[Elektrotechniker]

Also if you turn it so the the line is vertical with your line of sight it looks like it has very good divergence.:tinfoil:

I see what you did there. That's cheating :shhh:

 

[bobhaha]

Oh, I'm not familiar with Australian slang, I do know what else a "Down under" means ....

Sorry.

Yeah, would you mind taking a beamshot or two with beam focused to square?
I'd love to see that!

Also because of the fact that we are down under every one else

It was IgorT.

He hasn't been around for some time

Peace,
dave

Didn't FlamingPyro also have one? IIRC it was also TEC cooled.... or am I thinking of IgorT?