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Anyone know where I can find a Nichia NDB4816 or equivalent?

laser_maestro

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I am on the hunt for a single mode Blue LD and came across this beast, Nichia NDB4816. Cant find anyone on ebay selling it or find any hardware that uses it that I can extract it from. Has anyone been able to get their hands on these? Does Sony or Sharp have a blue single mode LD that has the same output power and that I can find on ebay?
 



Singlemode Laser

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I am on the hunt for a single mode Blue LD and came across this beast, Nichia NDB4816. Cant find anyone on ebay selling it or find any hardware that uses it that I can extract it from. Has anyone been able to get their hands on these? Does Sony or Sharp have a blue single mode LD that has the same output power and that I can find on ebay?
I have a few of them in my lab. As far as I know only Nichia sells these blue singlemode diodes speced for 500mW (I run them at 700mW with temperature stabilization now for more than half a year) for a bit more above than 2k $ per piece (got one engeenering sample from the first batch they sold almost 2 years ago)

Singlemode
inglemode

Only scientific applications and research have a use for them so you won't get them on ebay anytime soon (I would like too but that's live)

Singlemode
 

laser_maestro

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I have a few of them in my lab. As far as I know only Nichia sells these blue singlemode diodes speced for 500mW (I run them at 700mW with temperature stabilization now for more than half a year) for a bit more above than 2k $ per piece (got one engeenering sample from the first batch they sold almost 2 years ago)

Singlemode
inglemode

Only scientific applications and research have a use for them so you won't get them on ebay anytime soon (I would like too but that's live)

Singlemode

Thanks for the response M^2=1! 700mW out of a blue single mode LD is impressive! Just out of curiosity, are you firing CW and how many hours of on time do you think that diode has went through? At 2k a pop I would be afraid to fire one for more than half a minute at 200mW above rating (I rather take a nice vacation than find out on my own , or buy 100 20 dollar LDs).

Do you have any recommendations on any other brands to explore for single mode blue or violet LD that have at least half the power (~300mW-400mW) ?
 

ZRaffleticket

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See PLT5 450B for ~300mW

I don't think anybody here posted testing results on Sharp's GH04580A2G, being nobody has I'd err on the side of the osram diode being superior.

Any particular reason you need single mode over multimode?
 

Singlemode Laser

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See PLT5 450B for ~300mW

I don't think anybody here posted testing results on Sharp's GH04580A2G, being nobody has I'd err on the side of the osram diode being superior.

Any particular reason you need single mode over multimode?

The PLT5 450B is speced for 100mW, the Nichia for 500mW. Overdriving one diode at 3x the rating (and hugely reducing the lifetime) and comparing it to a non overdrived one is like apple and oranges. The Nichia can output 1000mW without seeing even a sign of thermal roll over with proper a heatsink.

Hopefully they will get cheaper soon or another company will figure out their recepy.

Singlemode
 

ZRaffleticket

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Absolutely true, but I argue it also goes down to use cases. Is the lifetime a problem for the OP? If its just a pointer project, $20 to replace a blown overdriven diode isn't too bad considering the cost of something actually specced there or higher. If it's for something scientific or being sold, then there probably are no cheaper options available than the ndb- diode. Ultimately same reason I asked "why not multimode", as there are a few multimode diodes with good divergence that would easily reach OP's power specifications.

For a handheld, I'm driving mine that hard and it's been running fine after a few years. In the case it dies, it's easy and cheap to replace.
 
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farbe2

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There are also these 500mW Nichia diodes that where used for show lasers way back. Sometimes a few pop up on eBay. These are Multimode but no where near as bad as the current >1,6W designs.
If i remember correctly, the divergence is around 1/2 to 1/3 of the PLTB450.

the Nichia can output 1000mW without seeing even a sign of thermal roll over with proper a heatsink.
Thats not the only consideration. Lifetime drops significantly not only after the knee but also do to electro migration do to current density.
So saying "2x output is ok because its before the knee" is dangerous. As you said, the drop in efficiency is do to thermal effects, so some diodes with better conductive material and/or thiner die base will show no knee before dying.

The PLTB450 can and does run at around 150°C (Depending on case temperature) die temperature without problems / hard dropping efficiency. Driving this diode at 2x the output at lower die (case) temperatures will not show significant drops but will kill the diode almost instantly.

The 100mW PLT5 450 die does only rise by 80°C even if overdriven to 400mW. Maximum operation temperature is specified with 150°C. one would even be safe at 70°C case temperature! However the diode lifetime will be low do to the high current density that accelerates electro migration, that is if the facet holds up to these high field strengths.

So depending on a use case, the 500mW "almost single mode" or the way overdriven 100mW Osram diode would be nice for show/pointer use.
Commercial Scientific use will definitely need the single mode 500mW Nichia diode, cost does not really matter there.

For home/hobby use (that NEED! the SM beam) i would use a tec to cool the 100mW PLT5 450B diode as low as possible and overdrive the heck out of it.
The low temperatures will somewhat slow the degradation and will reduce the current needed for these high output powers. Maybe buying 5 to select the one with lower threshold / higher efficiency. That way, i have one to replace the blown ones and can further extend the limited lifetime. While still keeping the budget low.
 




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