Any interest in high power 405nm diodes these days?

I have a chance to get a bunch of modules with an unknown 405nm laser diode that in testing here makes 1W at about 700mA and >1.4W at 1.0A. The modules are weirdly shaped and have a driver that I haven't fully reverse engineered, but also include a G-2 type collimating lens coated specifically for 405nm so they are very low loss. When I got some of these a few years ago I found it was fairly easy to extract the diode and the lens for use in more standard (i.e. Aixiz 12mm) modules. Is there any interest in high power near UV diodes there days?

Yeah i'm interested. PM me.

... me too, if you ship to Germany ...

Viktor

I buy a lot of 405nm diodes from DTR for glow in the dark work. His 16x BDR-209 have the same stats ~1.1W at 700mA although I run them closer to 450mA. I understand he pulls these from new blu-ray drive sleds.

If the cost were low enough to justify the effort and/or that colimation lens was something special, I'd be in for a few.

-David

I'll get pictures and more details soon. These are in fact multi-mode diodes, but the module includes anamorphic correction so the output is circularized. I test them all at 1250mA to make sure they can handle it, but recommend running them at 1.0A for 1.4-1.5W output. The threshold is around 225mA and fold-back doesn't happen until around 1300mA. Here is my preliminary power vs. current plot

https://docs.google.com/spreadsheets...it?usp=sharing

what's the spot size and divergence?
are the drivers analogue or TTL?

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Originally Posted by Junktronix

I'll get pictures and more details soon. These are in fact multi-mode diodes, but the module includes anamorphic correction so the output is circularized. I test them all at 1250mA to make sure they can handle it, but recommend running them at 1.0A for 1.4-1.5W output. The threshold is around 225mA and fold-back doesn't happen until around 1300mA. Here is my preliminary power vs. current plot

https://docs.google.com/spreadsheets...it?usp=sharing

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Here are some pictures. They are the weird shape because 20 of them were aimed at a small area in a high brightness video wall display module. The driver seems to have analog and ttl modulation, but the analog signal is 0 to /negative/ 0.15V. The diode supply is supposed to be 8.65V, though I'll see if anything melts with a 12V supply. The anamorphic correction is a single optic that I originally thought was just a weak lens used to aim the beam (it can be moved in X and Y, but is glued in position once aligned). The last couple of pictures show the collimated beam with and w/o the anamorphic lens. I'll get measurements and do the divergence calcs soon.

do i spy a linear actuator in there? is there someway to dynamically control focus?

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Originally Posted by Junktronix

Here are some pictures. They are the weird shape because 20 of them were aimed at a small area in a high brightness video wall display module. The driver seems to have analog and ttl modulation, but the analog signal is 0 to /negative/ 0.15V. The diode supply is supposed to be 8.65V, though I'll see if anything melts with a 12V supply. The anamorphic correction is a single optic that I originally thought was just a weak lens used to aim the beam (it can be moved in X and Y, but is glued in position once aligned). The last couple of pictures show the collimated beam with and w/o the anamorphic lens. I'll get measurements and do the divergence calcs soon.

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It is a teeny tiny stepper motor with a worm gear used to rotate an AR coated block of glass (quartz?) so as to offset the beam left/right by 2 or 3mm.

Hmmm. Being able to get a decent-ish corrected beam at more than the operating output of the single mode 16x diodes 405nm diodes may have some use for softer lines/fill-effects in glow in the dark art work. The fill take forever compared to outlines, so perhaps stacking two of these multimodes with 4X the power would cut that down significantly. I'm also interested to see what can be done with the other hardware as well.

-David

I was seeing some weird behavior using the built-in driver so I re-did my power and voltage versus current plot driving the diode directly. Turns out fold-back doesn't happen until around 1.5A with the diode making about 1.9W. I'd still recommend running at 1.0A for about 1.5W output. After I do beam measurements and divergence calcs, I'll spend some time trying to fully reverse engineer the driver board.

sounds great. what price are you asking?

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Originally Posted by Junktronix

I was seeing some weird behavior using the built-in driver so I re-did my power and voltage versus current plot driving the diode directly. Turns out fold-back doesn't happen until around 1.5A with the diode making about 1.9W. I'd still recommend running at 1.0A for about 1.5W output. After I do beam measurements and divergence calcs, I'll spend some time trying to fully reverse engineer the driver board.

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A bit more info - I measured the spot at 10m to be around 25 x 25mm (with the anamorphic correction) which gives a divergence of 2.5mrad.

I also plotted the 16X blu-ray diode power on the same chart as these guys so you can easily compare performance. Do note that I'm testing my diode with the anamorphic correction optic installed.

Might be interested in a few depending on pricing to round out the diode collection.

... nice find-- TY for sharing-- hak

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Originally Posted by Junktronix

A bit more info - I measured the spot at 10m to be around 25 x 25mm (with the anamorphic correction) which gives a divergence of 2.5mrad.

I also plotted the 16X blu-ray diode power on the same chart as these guys so you can easily compare performance. Do note that I'm testing my diode with the anamorphic correction optic installed.

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Thanks for this, Junktronix!

So stepping back with my glow in the dark hat on <edit - I really want a glow in the dark hat now>, I'm thinking two of these stacked to get 3W of fill beams as opposed to my current 750mw of slightly de-focused fill beam from one single mode 16x diode.

I wonder if due to the poor corrected beam specs on the multimode diode if stacking 4 of the 750mw might make more sense to get 3W of fill beam. (Fills take forever compared to doing tight outlines, so a more powerful fill beam is certainly attractive either way.)

Please let us know if you get some pricing on these so we can evaluate the cost/benefit further.

Cheers!

-David

The beam shape at the module is roughly 1mm x 4mm so it should be reasonably easy to knife-edge a couple of them. Or 2 pairs combined with a waveplate and PBS cube. I'll PM Photonlexicon pricing since I'll be asking more for them from the general public ;)

two pairs is a pretty scary amount of 405, but it would be really amazing to work with..

as long as you're not just burning up the wall.

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Originally Posted by Junktronix

The beam shape at the module is roughly 1mm x 4mm so it should be reasonably easy to knife-edge a couple of them. Or 2 pairs combined with a waveplate and PBS cube. I'll PM Photonlexicon pricing since I'll be asking more for them from the general public ;)

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I may be interested depending on price

I may also be interested depending on price, let us know if you can sell the module as is also.

Very interesting find...sending you a pm

Good to see there is some interest in these. I'm hoping some of you will figure out more about the modules and share with the rest of us. As incentive, I'll give 2 free bonus modules for the first person to figure out a way to use the built-in driver without needing a negative voltage for the modulation signal (+1 module for a complete reverse-engineered schematic) and for the first person to provide a decent 3D model of the module (+1 module if you share the design on Fusion360) to help people integrate them into their projects :)

I'm keeping the PL member pricing to PMs right now. PM me if I haven't already sent you PL pricing. To order, paypal $price x # of modules + $7.20 for Priority Mail small flat rate box to paypal@junktronix.com. International shipping by Priority Mail flat rate will be $35.25. I'll ship in a padded envelope by first class if you really want me to, but you must take all responsibility for loss or damage.

For now I don't have time to disassemble the modules to sell the diode and optics as individual components. If you want to extract the diode and don't have a press tool, it should be possible to saw the copper heat spreader it's pressed into and then split it open. The collimator can be extracted by heating the epoxy with a hot air gun and pressing it out with a soft object like a q-tip. I will, if you request it, desolder the driver board if you don't have a good, anti-static vacuum desoldering tool.

I'll test each module individually. Briefly at 1250mA to make sure they have lots of headroom, and then at 1000mA to check operating power. I'll guarantee they make > 1.4W @ 1000ma. Most have been closer to 1.5W.

I put the pinout of the driver board on a second tab in the spreadsheet

https://docs.google.com/spreadsheets...it?usp=sharing

I suspect the modulation input can be changed from the weird 0 to -0.15V to a more reasonable positive range by rewiring the signal to the non inverting input of the instrumentation amp and reducing the gain of the amp. However, please note that the 2 transistors in parallel on the driver board are rated for 1000mA and the driver behaves weirdly above that. I've run it up to 2A without killing it, but I'd definitely recommend using a different driver if you're going to push the diodes to 1000mA or more. The spreadsheet data were collected while driving the diode with an external driver. I've been using a current limited bench supply for all my testing to avoid any possibility of over-driving the diodes. Any suggestions for a good quality, reasonably priced 1.5A diode driver with analog or fast TTL modulation would be appreciated.

I have not yet tried driving the tiny stepper motor, but it's a simple 4 wire motor and should be easy to wire up. It should be ideal for knife-edging since the rotating glass block offsets the beam left/right by a few mm without changing the aiming.

I'm in for a couple and I intend to extract the diodes, stack 'em and run them with BBE's Simpledrive v2.5.

-David

For those interested in driving the stepper motor, the board these plugged into has an On Semi LB1935FA chip dedicated to each diode module. I'm guessing 20-50mA per phase.

http://www.onsemi.com/pub/Collateral/ENA2060-D.PDF

Another update. I found that the laser diode can be removed from the copper heat spreader by just bending the copper a bit. The diode pops out with zero stress or chance of damage like if you used a press tool.

On eBay now - https://www.ebay.com/itm/113257993344

characters. PM Sent.

These are much cheaper than what was quoted me from a few chinese sources. I'll definitely pick one up at some point.

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Originally Posted by Junktronix

Another update. I found that the laser diode can be removed from the copper heat spreader by just bending the copper a bit. The diode pops out with zero stress or chance of damage like if you used a press tool.

On eBay now - https://www.ebay.com/itm/113257993344

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What size is the diode itself? 9mm?

5.6mm with 2 isolated leads so no photodiode

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Originally Posted by Junktronix

5.6mm with 2 isolated leads so no photodiode

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This is great. My 16x just led'd so I'll pick this up asap. Thanks Junktronix.

A little more info about these. @Phritzler suggests (and I concur) that the diodes are most likely Sharp GH04W10A2GC. These are spec'd for 350mW CW and 1100mW pulsed. So running them at 1.5W CW is pushing them pretty hard. They are individually tested so I know they will work at that power, but one possible issue is that the wavelength shifts up at higher currents. I'll fire up the optical spectrum analyzer and get some measurements at various currents and add that data to the spreadsheet.

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Originally Posted by Junktronix

A little more info about these. @Phritzler suggests (and I concur) that the diodes are most likely Sharp GH04W10A2GC. These are spec'd for 350mW CW and 1100mW pulsed. So running them at 1.5W CW is pushing them pretty hard. . . . I'll fire up the optical spectrum analyzer and get some measurements at various currents and add that data to the spreadsheet.

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Thank you for the continued information, Junktronix. I've got two of them sitting on my bench, but I haven't fired them up. If they will fail over time if pushed >1W, then I'd say sticking with the BDR-209 16x 405nm from DTR probably make more sense for most people's needs. Those peak at 1.2W with a G2 lens and are single mode. I run mine at 750mw without issue.

It would still be nice to get that sled figured out though!

-David

Running the Sharp diodes at 1.0A is not pushing them any harder than running a 16X diode at 750mA so I don't think the lifetime will be any worse.

I've tested a few of the modules at 1.5W output and the wavelength shifts up to around 412nm. I suspect the 16X diodes do the same, but I don't have one here to test.

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Originally Posted by dkumpula

Thank you for the continued information, Junktronix. I've got two of them sitting on my bench, but I haven't fired them up. If they will fail over time if pushed >1W, then I'd say sticking with the BDR-209 16x 405nm from DTR probably make more sense for most people's needs. Those peak at 1.2W with a G2 lens and are single mode. I run mine at 750mw without issue.

It would still be nice to get that sled figured out though!

-David

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Originally Posted by Junktronix

Running the Sharp diodes at 1.0A is not pushing them any harder than running a 16X diode at 750mA so I don't think the lifetime will be any worse.

I've tested a few of the modules at 1.5W output and the wavelength shifts up to around 412nm. I suspect the 16X diodes do the same, but I don't have one here to test.

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Oh, just to clarify, I’m not running those BDR-209s to .75A, I’m running them around .46A so the output with a G2 lens is 750mw. I would doubt they’d hold out for long at .75A (1.18W output).

The shift up the spectrum when being overdriven is interesting. I wish it shifted the other way though!

David

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Originally Posted by dkumpula

Oh, just to clarify, I’m not running those BDR-209s to .75A, I’m running them around .46A so the output with a G2 lens is 750mw. I would doubt they’d hold out for long at .75A (1.18W output).

The shift up the spectrum when being overdrive is interesting. I wish it shifted the other way though!

David

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Yea 460mA is a good conservative current on the 209's and for sure still way more than the actual manufacturer rated if we had access to that info. I suggest 600mA as a max. When I did the original testing on them many were trying to get over 1W and lots of posts in first several pages of that thread had 750mA listed. Was not long after that it became evident that was too high as most the original builds died in short order. I did edit my posts with warnings about trying to get over 1W by pushing but so many still sell them as 1W diodes. I do know the 209's are reported to be much higher in wavelength. Either they shift a lot or maybe they are actually rated 410nm or something since all we have to go on is the community testing.

I have a formula I came up with and like to use with new diodes I offer that I don't have any long term data on for suggesting running currents. Tends to be pretty accurate when looking back after the diode has been around long enough there is a lot of data and feedback. Take the efficiency curve and go about 25%(single mode) or 20%(multimode) back of the knee for low duty cycle applications and 40% back for long duty cycle applications. The knee on the 209's where efficiency starts dropping off is about 800mA with foldback is around 900mA. that would be 600mA 25% back and 480mA for 40% back. Looking at the graph on these the knee looks to be around 1.2A with foldback @ 1.4A looking at the graph. That would make my guess that 960mA for 20% back and 720mA for 40% back. There are a lot of low duty cycle applicators but take pointers as an example for short duty cycle where long term degradation is not as much of a factor. Most deaths are LED or COD damage from harsh cycling, thermal damage from running too hot, or optical damage from contaminates which the multimode diodes have much higher tolerances for heat and electrical abuse. If you think about most probably will never see more than 100 hours if you use it 20 minutes every day that is over 4 years just to get to 100 hours.


1A is probably fine for the lower . The rated current on a datasheet is not a one size fits all as they are formulated to achieve the MTTF life ratings for end use they are marketing them for. Take the diodes marketed for use in projectors as alternative to LED's they underdrive them considerably to get a 20K-30K MTTF where some more general uses are formulated for a 500-5000 hour life rating.

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Originally Posted by DTR

I have a formula I came up with and like to use with new diodes I offer that I don't have any long term data on for suggesting running currents. Tends to be pretty accurate when looking back after the diode has been around long enough there is a lot of data and feedback. Take the efficiency curve and go about 25%(single mode) or 20%(multimode) back of the knee for low duty cycle applications and 40% back for long duty cycle applications. The knee on the 209's where efficiency starts dropping off is about 800mA with foldback is around 900mA. that would be 600mA 25% back and 480mA for 40% back. Looking at the graph on these the knee looks to be around 1.2A with foldback @ 1.4A looking at the graph. That would make my guess that 960mA for 20% back and 720mA for 40% back. There are a lot of low duty cycle applicators but take pointers as an example for short duty cycle where long term degradation is not as much of a factor. Most deaths are LED or COD damage from harsh cycling, thermal damage from running too hot, or optical damage from contaminates which the multimode diodes have much higher tolerances for heat and electrical abuse. If you think about most probably will never see more than 100 hours if you use it 20 minutes every day that is over 4 years just to get to 100 hours.

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Good advice, DTR! My experimentation building projectors with your single mode diodes over the years LED me (heehee, I couldn't resist that pun) to the same conclusion. Depending on the single mode diode, I back it off 25-40% from the knee. The reds and blues appear to be reasonably resilient enough to handle the ~25-30% back-off while greens need a good 40% back-off to survive (and I don't even run my lasers that often). I hope others follow your guidance and don't suffer from the consequences of being too power-hungry! ;)

-David