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

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

My Nubm44 build

astralist said:
I just watch an experiment on youtube with led and liquid nitrogen,
when they submerge a 450nm led to liquid nitrogen, the wavelength is shifted to longer value and looks like it's gone to 490nm

My question is, what if we keep this diode running below 25 Celcius, would it make the efficiency better AND wavelength shift happens, or will nothing happen?

Just curious, because AFAIK no one here running the diode in subzero temp.
Click to expand...

Styro has done testing as have others, but some diodes shift wavelength better than others, these blue phosphor pumpers seem to gain efficiency and power handling ability with chilling from the tests I have seen, the blues don't seem to shift color easily like the reds do with chilling.
 
Last edited:





I thought it would have to have every thing needed to measure a lasers output up to 20 Watt.......
 
I thought that I read the head needed to be stored in a humidity controlled enclosure and only taken out for short use, is that no longer the case?
 
RedCowboy said:
Styro has done testing as have others, but some diodes shift wavelength better than others, these blue phosphor pumpers seem to gain efficiency and power handling ability with chilling from the tests I have seen, the blues don't seem to shift color easily like the reds do with chilling.
Click to expand...

To which wavelength does the red shift to? higher or lower? it would be great if red diode shifted to the 593.5nm :eg:

Accutronitis said:
I thought it would have to have every thing needed to measure a lasers output up to 20 Watt.......
Click to expand...

It is indeed included everything to measure up to 20W

RedCowboy said:
I thought that I read the head needed to be stored in a humidity controlled enclosure and only taken out for short use, is that no longer the case?
Click to expand...

That is no longer the case, as this TEC is uncoated


Guys, btw i don't feel right discussing an OOT topic inside this thread :yabbem::yabbem::yabbem::yabbem::yabbem:
please go to the discussion thread instead:
http://laserpointerforums.com/f70/hyperion-lpm-vritonuzz-data-logger-platform-97102-6.html
 
Believe or not it is actually the other way. As the temperature increases so does the wavelength and vice versa. Styropyro successfully cooled a red laser diode to near yellow using liquid nitrogen. InGaN/GaN used in our blue and greens is not as tolerant to temperature tuning but you could notice a 5nm+ difference however. I can't remember the exact scientific reason why, but it is something to do with the band gap energy and the temperature. When lowering the temp you are reducing the energy producing heat (loss) and increasing the photonic energy (gain) instead hence lowering the wavelength. It is to do with gain and loss.

tuning_via_resonator.png


In order to tune a 450 up to 490 you would have to overdrive it, and of course you would never make it without killing the diode. It is possible for you to get 460nm+ but don't expect much more from a InGan. The NUBM07E's have proven to be the best InGaN based diodes to temperature tune. And this is because they can handle a higher current.
 
Last edited:
We have a clear forecast and a scheduled Astronomoy night tonight.

I was going to test my Nubm44 outdoors tonight.

But, I just turned it on to see if the beam was visible outdoors.

Pop Sound and burning smell. I think the driver just blew up.

This might explain the reading of 8.4 Watts. The driver might not have been set correctly when I bought it.

I have PM'd DTR about it.
 
Last edited:
  • Like
Reactions: GSS
Mosc007 said:
We have a clear forecast and a scheduled Astronomoy night tonight.

I was going to test my Nubm44 outdoors tonight.

But, I just turned it on to see if the beam was visible outdoors.

Pop Sound and burning smell. I think the driver just blew up.

This might explain the reading of 8.4 Watts. The driver might not have been set correctly when I bought it.

I have PM'd DTR about it.
Click to expand...

:cryyy: :cryyy: There's never a good time for that. :( I'll light a candle for your died solider, bummers :can:
 
Last edited:
I'm sorry to hear about that. I had a feeling this might happen. Over 8 watts is really pushed hard.
 
If it ran for a while I would not mind. All I got out of it was one LPM test. Then when I turned it on today before taking it with me instant pop of the driver. No beam output at all.

It seems like the driver was set to high. This was fully assembled in a 20mm module so I couldnt check anything.

I have bought quite a few diodes, modules, driver and lens's of DTR over the last 5 years. This is the first failure.
 
Last edited:
This is rare especially for DTR. I hope you get it resolved. DTR has excellent customer service from what I've experienced. :beer:
 
Let's hope it's the driver which actually dead, not the diode.

Having a NUBM44 which can be driven to 8.4W is more like a lucky item, even if you got a replacement you can't find one having similar efficiency.

BTW, i have one SXD driver which is popping, and clearly the IC is burned, but that because i accidentally installs battery with revere polarity. I haven't turned on this laser for years, it makes sense i completely forgot the polarity :banghead:
Too bad those driver is without revere protection. :(
 
I will pull it appart during the week. I am almost certain the driver IC popped and blew up. Just hope it didn't take the diode with it. I do have a current supply I can check the diode. Just low current will do.

Not sure how easy it will be to remove the driver though. DTR has thermal bonded it to the pill. Of course that's the right way. But might be hard to remove it without damaging the board.


No problem with polarity. I have dean's plugs on all my Lab style lasers. Can't connect them wrong once it's wired up. Maybe the driver shorted to the pill causing it to blow up.
 
Last edited:
Yea over 8W is way more than I would expect so it is probably right that more current was getting to the diode than it should. I set these to 4.5A unless asked for a different current. I would agree the best guess based on what you described without seeing is some type of issue with the driver. I can get you swapped out but please shoot it over before taking it apart so I can better troubleshoot it if you have not already.:beer:
 
DTR said:
Yea over 8W is way more than I would expect so it is probably right that more current was getting to the diode than it should. I set these to 4.5A unless asked for a different current. I would agree the best guess based on what you described without seeing is some type of issue with the driver. I can get you swapped out but please shoot it over before taking it apart so I can better troubleshoot it if you have not already.:beer:
Click to expand...


NP. I havn't even removed the module from the host yet. I will leave it as is and send it back. Hopefully shipping from Aus won't cost me to much.

I sent a PM to get your address.
 
Hope it works out for you, Mosc007. Jordan has always had the best customer service of all the members here that run businesses of a laser related nature, bar none. It is unfortunate that you are in Australia.
 
You must log in or register to reply here.





Back
Top