Dpss yag laser

[flecom]

hrmm, maybe by blue got dropped too? and all my mW's fell out of the box?

(sorry had to)

thats some serious power in a tiny package!!!

[LesioQ]

Well, pumping with 300W of 808nm would give say 65W of 1064nm, multimode, CW.
But I'm not sure if You're controlling temp in the water circuit ...
Piotr.K

[300EVIL]

Dude!
That head is SWEET! I want one!

[krazer]

Well, pumping with 300W of 808nm would give say 65W of 1064nm, multimode, CW.
But I'm not sure if You're controlling temp in the water circuit ...
Piotr.K

Now were getting close!

Running CW I am getting just over 40w, and as I noted earlier I haven't been able to measure the beam profile yet, but if I did my guessing right I should be running single mode. The resonator consists of a 0.75m HR and a plano OC that is 80% reflection, that are 18" apart.

Now for some fun stuff, I added in a small q-switch. Sadly it is undersized for this laser, and with the 80% OC it can only blank the output down to about 10w, but still adds a fair bit of umph

Here is a poor razor blade that I decided to try it out on:

First is a shot of the cutting process (sorry about the rigjob on the focusing lens, the only lens I had handy had a stupid diameter so I couldn't find a mount for it), a shot of after the center piece fell out, and a macro shot of the cut edge.

[mixedgas]

Go to a UPS facility, see the 3-4 foot drop into the sorting bin. See packages fall off unfenced convayors.. See your stuff land on other people's stuff! See other peoples stuff land on your stuff.

Find that since they are self insured, nothing less then a lawyer and the Warsaw convention get you paid...

Cost me at least 1500$ over the past 15 years. Including 700$ in one swoop.

I go to the post office or FEDEX for a reason, big stuff goes truck freight in a wooden outer case, with the inners on preloaded springs, or double foamed boxes...

Nice build Krazer, your the first one I've seen in a long time get donuts to lase something, will we be seeing a V fold in the near future, or a external doubler?

Steve

[krazer]

Ok I know its my failt for mentioning the B word in the thread, but please keep your gripes in the correct thread.

Sadly you probably won't be seeing much more till summer comes, I am headed back to school and the beast isn't coming with me. The long term plans for it is to get a beefier q-switch, add in the second pump module, and tweak the cavity a bit to try and extract a bit more power, my goal is to hit 100w q-switched with the pair of pumps. The doubler LBO out of the head survived, so I am planning to have a way to add that in for doubling extracavity for cutting materials that do not absorb 1064nm.

I designed the plate that the pumps attach to to be 'easily' removable (although I forgot about the electrical connections when I was planning that out) so that it could be swapped between heads to try something like a V-fold, but that is still probably a few years off. Plus what would I do with 50w CW green anyway


To answer a few trailing questions:
I am using a Lytron RC009 chiller, I measured max power with the head at 30c, which when running at 25A needs the water at 23c (which means that the effective thermal conductivity of each donut is .035C/W with about 2 gpm of flow, in case anyone is interested)

The rod is a 3mm rod, and the need for FAC was solved by a funky flow tube design The flow tube is very thick, and has a HR@808nm coating on it, with 5 slots in it, which are aligned with the diodes, so that the beam can enter through the slots, go through the rod, then reflect back for a second pass (or at least that is how I think it works). There also have to be some effects due to the thickness that I would need to do some ray tracing to understand.



It is hard to see how the flow works from the pictures, but you can download the solidworks model from my website, where it can be seen the flow for the rod and diodes is indeed separate. There are 2 holes on each of the end caps, one of them goes through the diffusers shown in the first post and then over the rod, the other one goes through the cooling channels in the diodes. I currently have it looped so that it goes through diodes then back out through the rod (that is how it was plumbed in the Avia head I got them out of), and it seems to work fine. I haven't measured the difference in the water temperature, but a rough calculation says there should be about 1c change between the inllet to outlet temperature of each bar. Coincidently, with 3 bars in series and the 23c water I am using that would put the rod exactly at 25c, so maybe someone at coherent was being smart when the picked the diodes wavelengths.


Anything in particular you guys would like to see it unleashed on before I head back to school? I want to let it drill a hole through a nice chunk of aluminum just to see how deep I can go and keep a clean edge, but I am open to suggestions

[dar303]

Fantastic! I vote for a piece of alu too, try 1cm maybe with air assist to get rid of debris.

[shrad]

maybe an angled hole? like 15 degrees, it would really tell about the beam quality and power if the edges are, well, like cutting

you could even try to make a carrot reaper

[krazer]

Well sadly I don't have time to build a gas assist for it, so for now this is done be just holding the part in front of the laser. I also ran into trouble with the aluminum, it reflects pretty well and I couldn't get good coupling, which in combination with the lack of any gas assist make cutting pretty dismal. So I switched back to steel, and took a few more pictures.


The fist one is shooting strait into the plate, the second one was taken at a pretty steep angle (15 degrees guessing). In both shots the cut is 250um in diameter, and its hard to see in these pictures since its really hard to focus in a hole (har har har), but the edge is suprisingly clean, probably flat to about 10um.

[shrad]

really great! makes a nice cutting tool