Inexpensive 1064nm DPSS?

[vbabbitt]

Hi all, happy to joint this forum!

I am working on some experiments where I need fairly high powered illumination (as opposed to using a collimated beam) of 1064nm IR. I see that there are a lot of high power green laser pointers available that frequency double 1064nm to 532nm, but I can't find inexpensive 1064nm DPSSs. The best I've been able to find are 3W 1064nm C-mount lasers for $120 on eBay. I need approximately 25 total optical watts illumination distributed over ~160cm^2, and I am hoping to perhaps find a supplier of green laser pointer components that would allow me to output 1064nm.

Can anyone point me in the right direction? Any advice on finding inexpensive multiple watt 1064nm lasers?

Thank you

 

[Cyparagon]

Why 25 watts and why 1064nm specifically? We can help you a lot better if you tell us what your project is rather than giving only specifications.

 

[vbabbitt]

Why 25 watts and why 1064nm specifically? We can help you a lot better if you tell us what your project is rather than giving only specifications.

Fair enough. This is for biology research. There may be some efficacy to using IR to increase the amount of ATP produced by cellular mitochondria. The point in the mitochondrial electron transport chain where Oxygen is used to produce ATP is Cytochrome C Oxidase (CCO). The hole where Oxygen is supposed to bind to is often (in most of us older guys) plugged by Nitric Oxide, reducing the cells energy production. It has been found that IR photons can provide the energy to release NO and allow the Mitochondria to "breath" again.

The 1064nm spec is because while a range of IR photons provide the effect as noted above, most photons are absorbed within the first few mm of skin, and the transmissivity of photons within the body peaks near 1072nm (which is also the IR transmissivity peak in water). Shorter wavelengths are generally absorbed and /or scattered by structures in live tissue. wavelengths longer than 1072 are absorbed by water in the body. So, if you are trying to effect tissue in the brain or the body deeper than a few mm, this is the wavelength to use. I'm asking about 1064nm only because the physics (I believe) makes creating a 1064nm laser much easier and cheaper than an actual 1072nm laser. I would prefer high power LEDs, but when I've tested several mfg's ~1050 - 1070nm High power LEDs, the efficiency of providing the actual 1060nm IR is extremely low.

The 25 watts optical is because research has shown a strange dose effect, and I believe there may be a two-photon absorption effect, so little efficacy at X joules/cm^2, but lots of efficacy at (X+C) joules/cm^2. I want to be able to experiment at varying levels of joules of near 1072 light energy per cm^2 during a treatment.

Any thoughts you have on inexpensive High power LEDs or laser diodes within the 1060-1080nm wavelength, I would really appreciate it.

 

[Cyparagon]

Okay, well High power CW YAG isn't cheap. Probably 5 figures. Unless you get lucky and find a scrap medical laser, I would consider living with the 'low' efficiency of LEDs.

 

[nabzim]

I wouldn't look into removing diodes from DPSS lasers. The IR pump diode is actually 808 nm. The Nd:YAG or Nd:YVO4 first lowers the frequency, or "stretches" the wavelength to 1064 nm, before entering the KTP (potassium titanyl phosphate) crystal which does the frequency-doubling, or "wavelength-halving" down to 532 nm.
This webpage "Professor Mark Csele's Homebuilt Lasers" has a lot of information on how many different types of lasers work, from a scientific standpoint. There is a page on DPSS lasers.
(***Sorry you have to Google the name, because the forum won't let me post a link since I'm still fairly new here, I need to have made at least 20 posts first. Probably to prevent spammer attacks)

It seems like, for such a powerful laser light source, of the wavelength you need, you're only solution is a YAG as Cyparagon suggested.

And, if this is truly for (real) scientific research, I don't understand why you would want an "inexpensive" laser in the first place. You need to be absolutely certain of all the variables involved, and inexpensive-things generally tend to lack the important data and specifications from the manufacturer or seller, which you need. You need a good quality laser from a reputable seller/manufacture. There are companies that make lasers specifically for scientific research. So, what is stopping you from writing a funding proposal to your institution?

 

[Encap]

Here is a used laser head 25W 1064nm on ebay for $800.00 if that helps. https://www.ebay.com/itm/Lee-Laser-...387981?hash=item5daabbb98d:g:P0UAAOSwf1Re55CO

 

[Alaskan]

Can the IR be pulsed? If so, how short may work? There are pulsed surplus 532 nm medical lasers available cheap which use high power pulsed 1064 nm to produce 532, as mentioned above. Laserscope units can be found on ebay for as little as 500 dollars. Otherwise you could look for a used laser welder. I bought a rated 20 watt output unit with a diode pumped YAG in it capable of 50 watts CW for 600 USD, but it requires a water chiller too, those can be found for a few hundred used too.

BTW, that 3 watt “1064” nm C- mount on ebay is closer to 1060 at 20 C. must be run hot to produce 1064.

 

[kecked]

You might look for a fiber laser. Reason I say this is that the output will be more even. I assume the size is based on a petrie dish. You also need to measure the light to assure stability. Very few lasers can produce that level of power for a sustained period. ... and not cost 25k. And be water cooled.

using leds you can homogenize the beam much better. finding the leds not sure. If I were running the experiment even illumination across my field would be right up there with optical density. Right tool right job.

 

[Alaskan]

You can find surplus diode pumped ND:YAG lasers, search ebay

Edit: A question for YAG guru's, why are CW pumped rods doped with less neodymium than a rod made for pulse flash tube pumping? What happens if you use a rod made for flashtube pulse pumping with a CW diode pump?