Cheap deep UV laser

[NiToNi]

I'm looking for a cheap deep UV laser for a school physics project (quantum, entangled photons). It needs to be below 350nm since the beam will be going through a β-Barium Borate (BBO) crystal which splits the beam into two of half the energy each (i.e. double the wavelength) and I want those exiting beams to be visible to the eye (i.e. max 700nm).

This is a high school project for my daughter on a low budget. The BBO is already expensive at a couple of hundred dollars although we may try to grow our own. However I cannot find any deep UV lasers that do not cost several thousand dollars. These are typically 213nm, 224nm, 248nm, 266nm, 272nm, 280nm, 325nm, 355nm etc. Here is an example of prices:

beamq.com/dpss-laser-solid-266nm400nm-uv-c-66_103.html

In contrast, I was hoping to find something from Sanwu, Jetlasers or even AliExpress, eBay, DX, DHGate, Banggood etc for a lot less, hopefully a couple of hundred dollars.

Are we not there yet in terms of cheaper technology...?

 

[kecked]

There is no known source of uv lasers that are in that pricerange. All are likely 10k or more. Likely you need 266nm and that will convert back to 532nm. I have never seen bbo do that. It usually frequency doubles. Though I guess conversion from 808 to 1064 is the same process. Just never seen it in uv back to visible. You will also likely need high peak power to do this so a pulsed q switch 266 unit is what you want. How do you plan to determine they are entangled? You’ll likely need very good temp control on the bbo so you need an oven too.

post a drawing

 

[AMooMooCow]

You could build a TEA nitrogen laser. I just think they’re super dangerous, but I don’t have the experience to say for sure *how* dangerous they are

edit: I’m also not a doctor (at least not anymore, not since the accident), but I’m not too sure of how much pulsed energy you’d need for proper laser type magic crystal lasing

 

[kecked]

https://www.stmarys-ca.edu/sites/default/files/attachments/files/ThompsonKurtFinalReport_0.pdf

This looks to be similar to what you want to do. Unfortunately there isn't a cheap laser source available to do this.
If all you want to do is model Bells Inequality you can do that with polarizers and a hene. If instead you want to do this paper then I am afraid you must find the right laser. Converting an argon to UV is not trivial and the optics will be expensive plus add in alignment.

IF you drop the visible part of this and use a spectrophotometer you might find some 355nm laser off ebay for a grand or two. I wonder if you can rent a source. There is a person on this forum that has a diode UV source but I doubt the beam is able to drive BBO to do the down conversion. I think you need some peak power to see any non linear anything. Its a power series as I suspect you well know.

TEA nitrogen does indeed give 337nm and high peak powers. That is an option. I have no idea of the polar nature of the resulting beam.

 

[Jim H]

https://www.stmarys-ca.edu/sites/default/files/attachments/files/ThompsonKurtFinalReport_0.pdf

This looks to be similar to what you want to do. Unfortunately there isn't a cheap laser source available to do this.
If all you want to do is model Bells Inequality you can do that with polarizers and a hene. If instead you want to do this paper then I am afraid you must find the right laser. Converting an argon to UV is not trivial and the optics will be expensive plus add in alignment.

IF you drop the visible part of this and use a spectrophotometer you might find some 355nm laser off ebay for a grand or two. I wonder if you can rent a source. There is a person on this forum that has a diode UV source but I doubt the beam is able to drive BBO to do the down conversion. I think you need some peak power to see any non linear anything. Its a power series as I suspect you well know.

TEA nitrogen does indeed give 337nm and high peak powers. That is an option. I have no idea of the polar nature of the resulting beam.

Not knowing that much about nonlinear crystals, could you frequency double a 532nm, and then use the resulting 266 nm UV for the experiment?