Flat Red Laser Diode Testing - 2nd Phase

[LarryDFW]

Finished some preliminary Flat Plastic Red diode testing last night.

From looking at the calibrated Scientech Power meter test results ...

I think that these diodes do have the capability to operate at higher power levels
than the LOC's we have been using.

The operating voltages were significantly lower than the LOC for the same operating currents.

Power levels (~400mw) did exceed the LOC graphs I have seen .

I would like to run a few more tests, before I post several different diode charts,
that I have run over the last few days.

I tested 3-Wire flat Reds from the 8X LG BR sleds donated for this testing by Daquin & Crazy Jay.

The 4-Wire flat Red was from a new LG 22X DVD burner that I finally purchased to obtain a current model
(photo from 5v1i5v0) :

LarryDFW

 

[Deleted member 8382]

Re: Flat Red Laser Diode Testing - 1st Phase

great, thx for your work.

 

[brtaman]

Re: Flat Red Laser Diode Testing - 1st Phase

Yeah definitely, I am interested to see your results/graphs with these babies. LOCs are pretty damn durable as it is, wonder how far we can take these with nice 650nm coated glass lenses...

 

[Gryphon]

Re: Flat Red Laser Diode Testing - 1st Phase

Looks promising, if this continues we may have to find a decent way of collimating these things for use in pointers

 

[daguin]

Re: Flat Red Laser Diode Testing - 1st Phase

Thanks for spearheading this.

I am looking forward to your results

++

Peace,
dave

 

[Asherz]

Re: Flat Red Laser Diode Testing - 1st Phase

This is looking hopeful, 400mW of red is quite impressive

 

[LarryDFW]

Re: Flat Red Laser Diode Testing - 1st Phase

Looks promising, if this continues we may have to find a decent way of collimating these things for use in pointers

I have figured a good lens assembly method for the 4-wire LG flat diode.

LarryDFW

 

[LarryDFW]

Re: Flat Red Laser Diode Testing - 1st Phase

These are the average test results from 2 different samples of
3-Wire Flat Plastic Red from the 8X LG BR sleds:

ma -- VDC - mw
-26 -- 1.72 -- 3
-53 -- 1.85 -- 6
-72 -- 1.90 -- 24
109-- 2.04 -- 53
149-- 2.16 -- 87
179-- 2.28 -- 118
221-- 2.39 -- 150
266-- 2.51 -- 183
317-- 2.65 -- 214
342-- 2.71 -- 238
376-- 2.79 -- 267
424-- 2.91 -- 300
489-- 3.09 -- 333
516-- 3.14 -- 354 - - vs - LOC - @ 3.45 VDC
Efficiency ~22%

EDIT- I have now run this diode at over 516 ma with very little heat.
Temp reached 84° F maximum w/ heat sink similar to aluminum host head.

Notice how the voltage was only 3.14 VDC even @ 516 ma.

About 91% of the LOC voltage @ 516ma.

More efficient for less heat generated.

Only one long F.L. lens was used from original factory sled mount.

LarryDFW

 

[Deleted member 8382]

Re: Flat Red Laser Diode Testing - 1st Phase

This really looks good!

 

[brtaman]

Re: Flat Red Laser Diode Testing - 1st Phase

Damn good efficiency.

How good do you think the sled lens is, efficiency wise?

 

[LarryDFW]

Re: Flat Red Laser Diode Testing - 1st Phase

Here are the average output levels from two different
4-Wire Flat Plastic Reds from the DVD LG 22X burner:

ma -- VDC - mw
-50 - 1.76 -- 17
-96 - 1.89 -- 61
131- 1.97 -- 96
192- 2.15 - 145 - vs- LOC -115mw
217- 2.21 - 178
267- 2.34 - 217
327- 2.47 - 251
378- 2.58 - 285
405- 2.64 - 303 - - Efficiency -28% . . Max Temp was 87° F after 15 min of testing
vs - - LOC - 290mw @ 3.16 VDC

Note-@460ma both of the test diodes failed

Notice how low the voltage was @ 405 ma (heat may have contributed).

Only 84% of the LOC voltage @ the same current.
About 5% more power @ the same current .
More efficient for less heat generated.

Only one long F.L. lens was used from factory sled mount,
giving an oval-shaped pattern.

LarryDFW

P.S. I also tested an earlier production 4-Wire Flat Red from a 20X Sony/NEC sled,
but the power results were less than the LOC diode.

 

[Deleted member 8382]

Re: Flat Red Laser Diode Testing - 1st Phase

Sorry for the stupid question but, how comes that we've never put our hands on those?

 

[brtaman]

Re: Flat Red Laser Diode Testing - 1st Phase

Sorry for the stupid question but, how comes that we've never put our hands on those?

Do you mean, why we haven't used these diodes in our builds in the past?

If so, we are a 5,6mm loving peoples dependant on Aixiz or meredith for modules, one would need machining skills and access to machine to be able to use these square plastic diodes. This is why the thread is so interesting.

 

[Deleted member 8382]

Re: Flat Red Laser Diode Testing - 1st Phase

Do you mean, why we haven't used these diodes in our builds in the past?

If so, we are a 5,6mm loving peoples dependant on Aixiz or meredith for modules, one would need machining skills and access to machine to be able to use these square plastic diodes. This is why the thread is so interesting.

oh okay lol

 

[roddenberry]

Re: Flat Red Laser Diode Testing - 1st Phase

I see that in the photograph, this little diode already comes in a compact little heat sink. If this is the standard format of this heat sink on all these drives using this particular diode, perhaps it would be interesting to machine a heat sink that would just fit this little casing, thus avoiding the trauma of breaking it apart to harvest this fragile-looking diode?

Those specs are truly interesting! Looks like there are some pretty smokin' lasers builds coming in our future!

What type of driver would be able to withstand this power, the latest rckstr drive?

- Robert

 

[HIMNL9]

Re: Flat Red Laser Diode Testing - 1st Phase

The problem is that you need to machine a rectangular hole inside the lens holder, with a hole to the thread part for pass the beam, and centered in the way that the chip remain in the center of the lens, once you insert it ..... and then, glue the diode inside the rectangular hole with thermal conductive glue (cause there is no way for press-fit it ) ..... not impossible, but hard to do (the heatsinks that are used are made molding the metal in a form, not working it with machines)

Once, i mounted one of these diodes (ot identical, it was a 18X IIRC, and had a different heatsink) on the back of an aixiz module ..... this one:

The heatsink had a conical extrusion in front, so i worked the aixiz part conic for match the heatsink, placed a pair of pieces of wire soldered in small holes at the back for keep it in placed, and then aligned and glued it with thermal conductive resin ..... but i made all this just for the curiosity to se if it was possible, proposing a similar work for commercial purpose is impossible

Edit: an alternative can be cutting the aixiz in the way that the diode, once inserted in the cut, will become pressed and with the chip at the same distance of a normal diode from the lens ..... but also in this way, you need at the end to align it laterally and then glue it with thermal conductive glue .....