Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

Single mode 445nm, 640nm and micro 532nm

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
Well, since no one seemed to have spare PCB's for my picoprojector, I decided to just go for it and rip the diodes. I have a feeling I may have cooked the green at some stage unfortunately, but there isn't any real info out there on how to properly drive them. If someone finds something I'll try it again.

But for now, I tried out the 445nm and 640nm diodes. Both running from LM317 drivers. The blue at 30mA, and the red at 90mA. I have a feeling the blue could go higher, and possibly the red too (50mW and 90mW respectively), but I'm not sure on their max currents yet. I know the red can take 220mA without blowing up, but it gets hot very quickly. Infact, when it gets too hot, it dims out really fast, and won't come back until it cools down again.

The blue doesn't seem to do this, but probably because it's only running at 30mA.

If anyone knows what kinds of currents I can get away with these _safely_, I'd love to know :)

Also, where would I go to get 3.8mm modules? Or adapters. These definitely need heatsinking, and I'm not going to run them again until I can get good heatsinking :)

Anyway, I leave you with some of the best beam profiles I've EVER seen for laser diodes:



Excuse the little black blob in the red on this picture, it's a peice of blu-tak I put there to focus the camera on, and forgot to take it off :eek:



And the diodes + green module compared to a 1/2W resistor:



So yeah, any info on safe current + 3.8mm modules would be nice :)

Cheers,
Dan
 

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
Just a bit of an update, I've got the teeeny green module lasing! Only for a few seconds though, and it required a lot of messing around. But, I think I've learnt what I need to do to get it running happily. I'm uploading a video at the moment.

EDIT: Video is 500MB! Gonna take a while! :(

Here is a little teaser though:

 
Last edited:

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
OK well, I've figured out sort of how to drive it.

It would appear the other 2 pins are for a small resistive heating element, it measures about 20 ohms.

I connected it up to an Arduino, and used a potentiometer to control a PWM signal into it, and I could adjust the potentiometer and the brightness would change with it.

Now I need to figure out what kind of current the diode itself can handle, then I can work on some circuitry to try keep the temp stable.
 

HaloBlu

New member
Joined
Dec 27, 2009
Messages
1,327
Likes
40
Points
0
Those are some nice diodes & that neat green module is a cute little thing.
~Edit~ I see it is those ones with a doubled 1064nm diode.
 
Last edited:

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,518
Likes
1,041
Points
113
^The pictures of the inside suggest it uses regular DPSS technology.
 

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
Well, managed to get it stable for the first ever beam shot!





It's soo cute! :)
 
Last edited:

532 with Envy

Well-known member
Joined
Jun 19, 2010
Messages
1,491
Likes
104
Points
63
Very nice work on the green there!
I was hoping someone with a bit more experience would get one up and running.

I didn't see, but were you able to get the whole unit(RGB) running at one time?

I'd rep ya.....but whats the point your already a super star;)

Edit: Watched your video...pretty surprised at just how sensitive it is to temperature.....I understand DPSS usually are, but not that sensitive...Either way, thanks for putting up the video!
 
Last edited:

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
Indeed, these are extremely temp sensitive :)

The little heating pad & xtal on top are so small, that changes happen almost instantly. It also means that the temp of the xtal changes depending on diode power, so there isn't going to be any real way of "setting and leaving" these modules, they're going to need some active stabilization. Kind of limits the portability of them.
 

holokidd

New member
Joined
Jan 6, 2012
Messages
21
Likes
2
Points
0
Can you provide any info on driving the DFB diode in the green unit. i just got my unit and will be testing it shortly.

and thanks for these priceless posts!
 

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
I'm still not completely sure of the rated current of the diode in it, since Corning doesn't give any specs on them, I doubt we'll know until someone blows one up unfortunately :(

I believe I have run the diode at 300mA without issues. vakuum on PL recommended 50mA 5V max heater power, so you should be good driving this directly from an Arduino and PWM'ing it to adjust the heater (Which is what I did for the beam shots).

Once it's at a set power, it's pretty damn stable, but I could never really get any more than a few mW out of it!

Looking at the module from the back, the 2 left pins are the diode, and the 2 right are the heater. I can't remember which is + and - of the diode, though I'd take a stab that left is +. Heater doesn't have a polarity of course. Just switch the diode wires around if it doesn't do anything.

It may not even lase at all until you get the temperature of the heater spot on, so try adjusting your heater and watching it to see if you get any light. If not, switch the diode wires and try again. If you still get nothing, maybe try letting the module warm up a bit, since they do run hot inside the projectors.
 

holokidd

New member
Joined
Jan 6, 2012
Messages
21
Likes
2
Points
0
Thanks for the info provided, i was able to get my G1000 to run stable for hours @ 90mw or so. Running the robust IR diode topped out arround 200mA, i tuned the crystal using 3VDC (off battries) and a trimming resistor made from a 10K potentometer. Now ill try and secrure everything and try to make a hologram with it ! ill post pictures later on. thanks you guys !
 

Things

New member
Joined
May 1, 2007
Messages
7,549
Likes
349
Points
0
You got 90mW out from 200mA diode current?? Wow!

Mind providing a bit more info regarding temps etc? Like overall module temperature, heater current etc. Would love to see if I can get that kind of power from mine :)
 
Last edited:

holokidd

New member
Joined
Jan 6, 2012
Messages
21
Likes
2
Points
0
sure no problem ill give info when i can... current output 100+ mw (after optics), amazingly only running about 26C, im using 5VDC @ 300mA Walwart to run the diode (actual was 200mA at diode), the heater was running less than 3v ... and it is running SLM (see hologram below!)
 
Last edited:




Top