Liquid Nitrogen changing wavelength of LEDs and Lasers

[luxilid]

This is pretty cool, excuse the pun:



Changing a red laser diode to yellow is particularly impressive!

[masterpj]

There is an old video of this being done with LEDS https://www.youtube.com/watch?v=4qgPhNHJPB8 The mode hopping is pretty common knowledge and planters also did a bit more actual experimenting then just fooling around. He also went as far to measure output power which also went up when he cryogenically froze the diode: https://www.youtube.com/watch?v=z8Eu...ature=youtu.be
I'm not sure why these older videos don't get the views as they are so much more informative.

[luxilid]

Thank you for posting those, indeed more informative than what I found!

[Vidal Wolf]

.. what they said!. Ive been doing that with LEDs and red diode lasers for a long time. run the red lasers at just above threshold and they really shift into the yellow. less current = less heat.

[Draco]

Sadly this was another reason one of my employers would not let me near there liquid nitrogen tanks

[buffo]

Get some yourself and experiment at home!

Liquid nitrogen is amazingly affordable. You can rent a 40 liter dewar for around a dollar per day, and to get it filled costs you less than 50 bucks. So basically it's about as cheap as buying a liter of soda from a vending machine.

Check around for an industrial gas supplier in your area. (Airgas Products, Praxair, etc) Give them a call and ask for a rate quote for their smallest dewar of LN2. You'll be pleasantly surprised at how affordable it is.

Just be sure to take proper cryogenic precautions! You can really hurt yourself if you don't know what you're doing. They will sell you the proper gloves if you don't have them.

Also, this is important: always, ALWAYS wear proper eye protection! Skin burns are bad, but cryogenic burns to the eye are really bad...

Adam

[masterpj]

Get some yourself and experiment at home!

Liquid nitrogen is amazingly affordable. You can rent a 40 liter dewar for around a dollar per day, and to get it filled costs you less than 50 bucks. So basically it's about as cheap as buying a liter of soda from a vending machine.

Check around for an industrial gas supplier in your area. (Airgas Products, Praxair, etc) Give them a call and ask for a rate quote for their smallest dewar of LN2. You'll be pleasantly surprised at how affordable it is.

Just be sure to take proper cryogenic precautions! You can really hurt yourself if you don't know what you're doing. They will sell you the proper gloves if you don't have them.

Also, this is important: always, ALWAYS wear proper eye protection! Skin burns are bad, but cryogenic burns to the eye are really bad...

Adam

I wish Adam! Maybe there it is cheap like dry ice is available and used by some stores, but here it's not because its dangerous and they want to make it harder to get to avoid serious injuries and from kiddies putting dry ice into sealed bottles or sealed containers. I also did call most if not all nearby gas suppliers ~1 year ago for a experiment to force cool laser scanners and they had either huge minimum quantity orders or they were just really expensive.

The only source I had for dry ice was a CO2 Fire extinguisher using a cloth wrapped in front of the nozzle.

It is still obtainable but even when I tried with for instance dry ice.. It was rediculously expensive and the better suppliers were in belgium and the transport for it was expensive.

[buffo]

I didn't know it was so expensive in the Netherlands. It is very cheap here.

If you can't find anyone who will sell you liquid nitrogen at a reasonable price, you can always make it yourself. Search for "DIY Liquid Nitrogen" and you will find several sites that explain exactly how to construct your own cryo-cooler for less than $600.

Last year at SELEM we had one set up in one of the dressing rooms. It made about a liter of liquid nitrogen per day.

Adam

[masterpj]

I would love to make one but right now I dont have the time or money I would love to make one sometime.. that being said if nitrogen gas can be obtained without overspending there is also a lot of hazards involved fire related because liquid oxygen is also created. However I wanted to supercool scanner just as an experiment related to tuning scanners. For instance with the lw50k you have to let the scanners warm up to get the circkle inside of the square.. bufore that its bigger meaning actually better performance so I wanted to see if extreme cooling would jield even more improved performance and gain and after that make the conclusion if its worth in making a small water cooled scanner block just to get that extra bit of performance.

[planters]

Generally, LN2 is no more expensive than dry ice. It is a lot colder and easier to store because dewars are available for rent or for sale on eBay.