New laser... My dreams have come true.

[GooeyGus]

Hey Guys, I haven't been around in a while but I just had to get back to the laser scene, because It looks like I FINALLY have a mixed gas SP 165 on my hands!!!

I drove down to SoCal (22 hours each way) last weekend to pick this laser up from dsli_jon. He had a hunch that this was probably a whitelight laser for several reasons, but had never fired it up.

Well, I took her home and had a chance to fire it up yesterday. The tube looks like it is in SUPER great shape... the glass which contains the water isn't even discolored a tiny bit. The tube itself looks brand new.

ANYWAY... after I blasted some current down the bore, here's what I came up with:



A nice pale white discharge. Not quite as ultra-white as a pure Kr tube.

So at this point I'm 99.9% certain this is a mixed gas tube. I haven't gotten it lasing yet, as I am still trying to get it aligned.

I am using a set of coherent whitelight optics, with little adapter rings so they fit into the spectra holders.

I only had about an hour to try to align it before my PSU took a dump. I was able to get the HR dialed in, but haven't gotten a flash of coherent light yet. I think the PSU blew an SCR.... luckily I now have about 5 extra power supplies. I just didn't feel like hooking everything back up to another supply, so I called it a night. Hopefully I'll be getting a beam this weekend!!!

Here is another shot of the tube while it's turned off. Sorry for the poor quality pictures. When I fire it up again this weekend I'll get out my good camera and take some glamour shots!

Notice the huge getter behind the cathode... my Ar 168 doesn't have that.



And an overall shot (crappy lighting)





Thanks for lookin! I just wanted to share my new toy. If anyone has any alignment tips for me, please let me know! In the past I've only had to align one mirror, which is a piece of cake for me, but I've never aligned the entire cavity from scratch.

[Laser Ben]

Pull one mirror, shoot a laser down the bore, centering it on each end, then align the far mirror to shoot the beam back to the aperture of the alignment laser. Then insert the close mirror and align it to reflect the beam back to the aperture. That will get you close, then align the rest once you get a flash.

[GooeyGus]

I'll shoot the bore if I have to, but I'm trying to avoid it.

I aligned the HR by pulling the OC mirror and adjusting the HR until a bright spot moved into the center of the "plasma light" created by the tube. I was told that once this bright spot is in the center of the main larger spot, the HR is very close to being aligned.

[mixedgas]

I'll shoot the bore if I have to, but I'm trying to avoid it.

I aligned the HR by pulling the OC mirror and adjusting the HR until a bright spot moved into the center of the "plasma light" created by the tube. I was told that once this bright spot is in the center of the main larger spot, the HR is very close to being aligned.

If you dont get it within the first hour of trying, reach for the hene. Coherent does some nasty radi on their optics, which extracts a lot of power, but the numerical stability is poor until you are really zeroed in, which is why coherent has the magnificent reduction drives on their adjustments... Put the hene at the back of the laser, shoot forwards to two mirror mounts that fold the hene down the bore.. This is done to get you a double optical lever, as those mirrors may be a bit near critical confocal. You should be a bit better off as the sp cavity is a tad shorter then the coherent.. This is past experience talking, Coherent also put a radius on the output side of the OC sometimes, for collimation, and this can cause confusion..

Steve

[mixedgas]

I'll shoot the bore if I have to, but I'm trying to avoid it.

I aligned the HR by pulling the OC mirror and adjusting the HR until a bright spot moved into the center of the "plasma light" created by the tube. I was told that once this bright spot is in the center of the main larger spot, the HR is very close to being aligned.

If you dont get it within the first hour of trying, reach for the hene. Coherent does some nasty radi on their optics, which extracts a lot of power, but the stability is poor until you are really zeroed in, which is why coherent has the magnificent reduction drives on their adjustments... Put the hene at the back of the laser, shoot forwards to two mirror mounts that fold the hene down the bore.. This is done to get you a double optical lever, as those mirrors may be a bit near critical confocal. You should be a bit better off as the sp cavity is a tad shorter then the coherent.. This is past experience talking, Coherent also put a radius on the output side of the OC sometimes, for collimation, and this can cause confusion..

Oh, and you can align with argon optics if you have a pair.. Then switch one at a time and find lasing.

Steve

[GooeyGus]

Using my argon optics is a fantastic idea! I didn't even think of that. I'll give it a shot tomorrow and see if I can get her going.

[drlava]

Gorgeous , Gooey. You've really stepped up a few notches of complexity/love with that one!

[Ed-laserproductions.ca]

make sure to slide the Brewster covers back before you try to walk the tube. Sometime the gimbles can be a bit finicky if they haven't been used for a while. if you done have the covers back you can snap a stem

Also if you get it to lase make sure the sacrificial anode is hooked up. Probably is but if it isn't it can reduce the lifespan of the tube a lot.

[GooeyGus]

STILL no beam... I tried for probably 5 hours today.

One thing that concerns me is that there is some "junk" in the tube at the anode end. It looks like tiny tiny tiny grains of sand. There doesn't look to be any crap built up on the brewsters, they look fine, but theres still this 'debris' in the tube. I tilted the tube and gently tapped the end until the little tiny grains of stuff moved into a dip in the glass (where the gas return wraps around the stem) so it was out of the way. It doesn't look like it would prevent lasing but I still dont like the fact that it is there... no idea of what it could be.

I fired my yellow HeNe down the bore, the beam passes through without any problems. My setup was horrible so I still couldn't get a beam.

Anyway, here's a pretty picture:

[Laserman532]

dang, I was in toledo wa just two days ago. Ok debris dont worry about, I would be more concerned about the optics and the curvature you are using. you will want a flat hr and a 4m oc is ideal you could go with a 4 and 4 but your performance wont be there. if you get a good spot off the hr in the center of the fluorescence and can run her at 30 amps you should be able to rock the OC end and get a flash.

I am available for a field call...sort of

edit - appears to be a re process job, color looks good but not sure how straight it is.

this laser should not need to be shot with another laser, it has enough gain to go on its own. shooting it is ok, if you just want the practice lol