Identifying output by physical attributes

[JLSE]

Okay, so as seen in my other thread, I have to test out some 808's in a 9mm package.
I have noticed a possible trend in the diodes, that has prompted the following question...

The wires bonded to the chip of an 808nm LD seen in a 1W usually totals 4. In a 500mW
typically 2 wires are seen.

I have some 9mm's that wont lase at 360mA where the verified 1W LD's will hit 150mW out on average.

I had not noticed it immediately, but the same LD's that has the higher threshold has 8
as pictured below.

Can it be safely assumed that being from the same manufacturer, and no visible difference in wire gauge, that this is a 2W??

Would it also be safe to assume that a 5W would have 18-20, or 8 being the max just a larger gauge?

Is there a pattern here that can give an idea as to their intended output?


If anybody has a 2 or 5W LD, if they can have a look under a magnifyer and count the leads bonded to the die, it would be very helpful.

If you cant see the actual wires due to the narrow view through the facet, counting what looks like tiny balls
on the ends of the leads will also be fine...

The LD's ive tested so far are coming in with 25% efficiency in a jig setup and hastily mounted Nd YV04 / KTP.

I do not wish to kill any of these if there is a simple and reliable means of first identifying...

Thanks :beer:


*EDIT*

Im also finding LD's with 6 wires. These can hit 10mW at 360mA while the 8 lead will not light.

So seeing as the threshold is increasing with the higher number of leads bonded to the die,
one could come to the conclusion that there is a in fact a trend.

My small bench supply only puts out 360mA adjustable from 0, but it would seem that im going to
have no choice in finishing my 5A adjustable to move forward with the smaller LD's.

The good news is, these are all appearing to be hearty 808's, and from what the seller has told me,
and the data included, these were made in the USA :drool:

The level of QC is a welcome thing in this case, especially considering I have no way to accurately
measure wavelength.

We all can get a rough idea with the visible spectrum, but when it comes to IR, there are so many
variations of the 800-900nm LD's in circulation.... Makes it hard to narrow down. Luckily I can test
these with a crystal set, and go by previous verified builds and % of conversion to 532...

 

[Meatball]

I have a couple 2W 9mms to take a peak at. I'll let you know exactly what I see when I find them!

 

[JLSE]

Thanks :beer:

What were the origin to your LD's?? Are they Heruu LD's by any chance?

If they are the Boston Laser LD's, it will be a good made in the US comparison.
My problem with LD's from china, is that they cut too many corners and may not lend
any valid info.

Im going to also dig up spent LD's that I have from snoctony, and see.
It was his diodes that partnered up for a 30% conversion to 532nm in
my first labby build. I know his are made in China, and were near spot on
808 (guessing) with such a great conversion... I am curious to see if they
also have 4 wires bonded.

 

[lasersbee]

Get yourself an IR indicator card if you want to see the
IR beam profile in the visible spectrum...

It would be a logical assumption for the same manufacturer
and the same wavelength that more of the same diameter
bonding wires would allow more current to flow..

As you already know... usually the higher the laser's power
is rated the higher the threshold current.

Here's some data on a 1Watt 808nm LD....

AL808T1000​

CW output power (mW) 1000​

Peak wavelength (nm) 808[FONT=ËÎÌå][FONT=ËÎÌå]±​

​

10​

Spectral width (nm) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]5​

Threshold current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]300​

Operating current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]1400​

Operating voltage (V) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]2.2​

[/FONT][/FONT]
and a 2Watt 808nm LD...

AL808T2000​

CW output power (mW) 2000​

Peak wavelength (nm) 808[FONT=ËÎÌå][FONT=ËÎÌå]±10[/FONT][/FONT]​

Spectral width (nm) [FONT=ËÎÌå][FONT=ËÎÌå]≤5[/FONT][/FONT]​

Threshold current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤700[/FONT][/FONT]​

Operating current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤2800[/FONT][/FONT]​

Operating voltage (V) [FONT=ËÎÌå][FONT=ËÎÌå]≤2.2[/FONT][/FONT]​

That is why you are not getting lasing from 360mA...IMO

BTW... Why have you not built an LM317 Current Driver.... :thinking:
It goes near 1.5 Amps with some good heatsinking...


Jerry

 

[Wizzard]

Has anybody thought of carefully electroplating gold/copper across those leads, shoring them up significantly? Could be done easily, considering water's surface tension.

 

[JLSE]

Get yourself an IR indicator card if you want to see the
IR beam profile in the visible spectrum...

It would be a logical assumption for the same manufacturer
and the same wavelength that more of the same diameter
bonding wires would allow more current to flow..

As you already know... usually the higher the laser's power
is rated the higher the threshold current.

Here's some data on a 1Watt 808nm LD....

AL808T1000​

CW output power (mW) 1000​

Peak wavelength (nm) 808[FONT=ËÎÌå][FONT=ËÎÌå]±​

​

10​

Spectral width (nm) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]5​

Threshold current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]300​

Operating current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]1400​

Operating voltage (V) [FONT=ËÎÌå][FONT=ËÎÌå]≤[/FONT][/FONT]2.2​

[/FONT][/FONT]
and a 2Watt 808nm LD...

AL808T2000​

CW output power (mW) 2000​

Peak wavelength (nm) 808[FONT=ËÎÌå][FONT=ËÎÌå]±10[/FONT][/FONT]​

Spectral width (nm) [FONT=ËÎÌå][FONT=ËÎÌå]≤5[/FONT][/FONT]​

Threshold current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤700[/FONT][/FONT]​

Operating current (A) [FONT=ËÎÌå][FONT=ËÎÌå]≤2800[/FONT][/FONT]​

Operating voltage (V) [FONT=ËÎÌå][FONT=ËÎÌå]≤2.2[/FONT][/FONT]​

That is why you are not getting lasing from 360mA...IMO

BTW... Why have you not built an LM317 Current Driver.... :thinking:
It goes near 1.5 Amps with some good heatsinking...


Jerry

Thanks for the info Jerry, if you get the oppourtunity,
id really like to know how many wires are on those die's.
Are those snoctony LD's as well?

Agreed, 360mA is low, but was just using as the highest my small
bench supply gives.

I have the board in front of me and am just finishing up .
It will be good to 5A with the steel cased T-03 LMXXX

I had another, but it was breadboard and was only good to 1.2A
With all the 808's I have to test 5A is going to cover the cmounts
and 9mm's. I still have to make another that goes to at least 80A

The 5A ver will also be with full linear control and is perfect for these
tests.

Im just looking for a trend to classify the LD's. There has to be a standard
that we can go by, but this may not be the case when comparing LD's
made in different countries..

All the same, it will be interesting if there is in fact some merit to go along
with it.

Also to view, I just use a sony cam with night shot.. It gives me a clear picture
on my monitor and an added level of safety on top of the goggles..

 

[AUTO XX]

What components are you using for the linear driver at 1.5A?
I have only made one with a lm350 so far but I seem to have at least 15 components in the mail at any given time these days.
*I really need to find a good local supplier* lol
I have (5) 808nm 1watters coming as well and I'd like to have a driver made up to run them when they get here

 

[JLSE]

What components are you using for the linear driver at 1.5A?
I have only made one with a lm350 so far but I seem to have at least 15 components in the mail at any given time these days.
*I really need to find a good local supplier* lol
I have (5) 808nm 1watters coming as well and I'd like to have a driver made up to run them when they get here

Because I sell these with my lasers (labby's) I dont publicly offer info, but can send you
a PM for personal use...

:beer:

 

[RA_pierce]

I've got a few C-mounts.
2W rating, 8 wires.

 

[JLSE]

I've got a few C-mounts.
2W rating, 8 wires.

Hmm, the plot thickens.. Thanks RA..

Do you by any chance know the origin?

 

[RA_pierce]

Hmm, the plot thickens.. Thanks RA..

Do you by any chance know the origin?

This one is from Snoctony on E-bay.

I wish I kept some of the 9mm open cans I had...

 

[JLSE]

This one is from Snoctony on E-bay.

I wish I kept some of the 9mm open cans I had...

Thanks.. Not to worry, im sure there is enough info around to figure this out.

LOL< you mean you dont have an LD graveyard? Im an LD hoarder

I think ive saved every burned or damaged LD since I began.
Its a reminder of how costly mistakes can be with lasers.
Also its almost as if you grow a sentimental attachment,
well that and they dont take up much room anyhow.

I was even thinking of making a gold nugget with all the
platting. Wearing my LD graveyard on a necklace would
also be kinda cool

 

[RA_pierce]

Thanks.. Not to worry, im sure there is enough info around to figure this out.

LOL< you mean you dont have an LD graveyard? Im an LD hoarder

I think ive saved every burned or damaged LD since I began.
Its a reminder of how costly mistakes can be with lasers.
Also its almost as if you grow a sentimental attachment,
well that and they dont take up much room anyhow.

I was even thinking of making a gold nugget with all the
platting. Wearing my LD graveyard on a necklace would
also be kinda cool

I have a film container with about $300 worth of diodes in it. Not that much... I try not to toast the high-dollar diodes.
I have a few toasted 5.6mm open can 808s from various cheap greenies.
Also a 9mm from a DX "200mW" garbage module. It has 3 wires. Maybe 4, but I can't tell because it's really fried.

 

[lasersbee]

Just pulled out a few working and damaged 808nm LDs
Here is what I got... 0ne was a 980nm...

Power-------Sply-------Case-----Leads

200mW ----- ????? ----- 5.6mm ----- 2
1 Watt ----- Snoct ----- C-Mnt ----- 4
2 Watt ----- Snoct ----- C-Mnt ----- 6
2 Watt ----- ????? ----- 9.0mm ----- 4
3 Watt ----- Snoct ----- C-Mnt ----- 10
3 Watt ----- ????? ----- C-Mnt ------ 8 (980nm)
3 Watt ----- O-Like ---- C-Mnt ------ 5 (from 2.4Watt Labby)
5 Watt ----- Snoct ----- TO-3 ------ 12-14 (hard to see into TO-3)

Hope this helps... None of the wires were missing..
I could clearly see the Weld spots on all the C-Mounts.

I think another additional good way to classify them
could be by Threshold Current..


Jerry

 

[JLSE]

Just pulled out a few working and damaged 808nm LDs
Here is what I got... 0ne was a 980nm...

Power-------Sply-------Case-----Leads

200mW ----- ????? ----- 5.6mm ----- 2
1 Watt ----- Snoct ----- C-Mnt ----- 4
2 Watt ----- Snoct ----- C-Mnt ----- 6
2 Watt ----- ????? ----- 9.0mm ----- 4
3 Watt ----- Snoct ----- C-Mnt ----- 10
3 Watt ----- ????? ----- C-Mnt ------ 8 (980nm)
3 Watt ----- O-Like ---- C-Mnt ------ 5 (from 2.4Watt Labby)
5 Watt ----- Snoct ----- TO-3 ------ 12-14 (hard to see into TO-3)

Hope this helps... None of the wires were missing..
I could clearly see the Weld spots on all the C-Mounts.

I think another additional good way to classify them
could be by Threshold Current..


Jerry

Thanks for the additional info... Every bit helps.


I guess there is for no certainty if going by leads,
where as threshold in most cases will be more accurate.

From what I have seen, and your numbers
id have to say that snoc's diodes seem to be
similar to those made in the US.

What I find odd with his LD's is the jump of 4 leads between
a 2 and 3W, and the unknown 2W only having 4??.

So either there is a difference in lead gauge, cutting
corners, or there is consistant differences between c-mount
and the 9mm package.

I have noticed with many cmounts that the lead wires are
usually much smaller, but more of them. Of course this
may not always be the case, and c-mounts may be harder
to identify in this fashion.

If anything, im thinking the ammount of leads will only be good
to give a ballpark idea of unidentified LD's.

The problem with threshold current, is in some cases like the
Heruu. grab bag diodes, they were classed as 'off spec', so
while their threshold can be high, it doesnt mean anything other
than off spec and didnt pass QC.

Using the threshold to identify can sometimes mean a 1W
can have a threshold of 700mA, looking like a 2W, but then
you feed it 2800mA which is the operating current for a 2W
and p00f.

So im thinking for all future testing, I will first start by categorizing
by a quick visula inspection and lead wire count, then powering up,
find the threshold and continue from there.

At least with this scenario, the chances of blowing up LD's will be
avoided in most instances. There will always be the exceptions,
but it puts you into the ballpark figure.

I went through Snoctony's items on ebay and compiled a quick
list of his diodes. These seem to be the most common values
for 808's that ive seen.


Ith-------Po--------If

100ma - .2W - 290mA
150ma - .5W - 650mA
300ma - 1W - 1400mA
700ma - 2W - 2800mA
1000ma - 3W - 3500mA
1100ma - 5W - 5200mA
5000ma - 20W - 25A
12A - 40W - - 50A

 

[BShanahan14rulz]

*logic fail*