Rhodamine 6g & 532nm

[Stoney3K]

C) That's a very kind offer. So far I've been able to do just about everything with a drillpress and a Dremel (including a laser mirror mount -- http://www.jossresearch.org/pictures...mountX.10c.jpg -- pseudostereo macrophoto for cross-eyed viewing), but there are some limits. We'll see how it goes. Again, though, many thanks.

Slightly OT here, but that mirror mount looks pretty slick considering it's made out of few things more than a set of angle brackets. The brasswork is amazing -- do you have any indication of the scale of this thing?

Permission to copy the design and make a kinematic mirror mount 'inspired' by it? Should be fairly easy to do when you look at it.

[jonsinger]

Slightly OT here, but that mirror mount looks pretty slick considering it's made out of few things more than a set of angle brackets. The brasswork is amazing -- do you have any indication of the scale of this thing?

Permission to copy the design and make a kinematic mirror mount 'inspired' by it? Should be fairly easy to do when you look at it.

Hi.

The brass is square cross-section tubing from the hobby shop; I used it to turn pairs of angle brackets into rather stiff structures. The problem is mixed materials, which can cause thermal expansion issues if the mount is in variable conditions. (Frankly, using epoxy to hold things together probably creates the same issue.)

I do have an indication of scale, though it's a bit peculiar: the thing that looks like a faucet aerator for a sink is, in fact, a faucet aerator. I think the mirror in it is half an inch across.

You can certainly copy the design. If you publish yours, I would deeply appreciate it if you cite mine as inspiration. The entire [slightly wacko] story of what it took me to get there is at http://www.jossresearch.org/tjiirrs/013.html I tried a bunch of stuff along the way, some of which definitely didn't want to work the way I thought it should, and there are a couple tweaky details, so you may want to do a quick skim over the page. One last thing, which I think I mentioned on the page (but I'm not sure, so I'll say it here anyway) -- if you look carefully at that photo, you'll see that the smaller pair of angles is mounted on the base, and the larger pair is out in the air. That's backwards. I wanted the larger set tied to the base, so that I wouldn't have to worry about the movable set running into the bench. This explains the extra rectangular brass tube between the mount and the base, which shouldn't have to be there; it holds everything up in the air a bit.

Cheers --
jon

[dsli_jon]

Heyas -

...Sorry for the 'quick detour', but just thought you might like to see some '10W Red shots to dye-for'.. '..dye... for', Get it?



..and the 'test shot' doesn't do-justice to the beam-qual, at-all - the thing (properly-collimated, of course..) is like a 171-beam....
Can't wait till I can have the time to start on the 'MegaRGB'... drool..

peace...
j

[planters]

I think your headed in the right direction. The very high beam quality of the dye output as well as the wavelength flexibility which allows coverage at wavelengths (longer than 532 of course) that are essentially unavailable otherwise is exciting Also, I don't think the concern that these KTP/dye systems are large and power hungry is justified. I doubt that the few existing 30+ W RGB projectors are being lunged around from show to show. And if not transported then access to 220V AC should be relatively common.

[jonsinger]

Hi.

I now have the dye circulator working, the dye jet mostly behaving itself at perhaps 22 psi (it still overruns the return pipe if I turn it up much higher), though it is leaking someplace, and slowly fills the CR-599 with dye solution. Gargh. At least it isn't fussing and splashing.

I am attempting to align the mirrors, a process that is slightly hampered by the fact that the text of the alignment procedure refers to diagrams that are not present in the PDF file. Fortunately, as I go through the steps I mostly see what they're talking about.

At this point I could swear that I have seen one brief moment of lasing, but I haven't been able to get back to it. Think I'm going to redo the alignment process from scratch, and we'll see how that goes.

Cheers --
jon

[planters]

Jonsinger,
Just to review, what drive laser are you using? Never having even seen a dye jet laser I'm curious about the turn on/turn off process. Isn't there a lot of spray at that time? I wonder about the shape of the free component of the jet. If not plane parallel, doesn't it act as an active maybe even dynamic optical element? The fact these things obviously do work fascinates me. Good luck!

[lls@laservideo.com]

Yes the jet is a part of the optical cavity. The jet flow in a 599 is continuous and the Coherent jet is actually a small dog bone shape. As the dye exits the jet, the curves of the dog bone pull the center area flat and parallel and that is where you want the pump beam to hit. The Coherent jet is very different form the old Spectra dye jet.

If anyone is interested, I have several 599OEM dye heads and 1 circulator for sale as well as different BRFs and some fairy narrow output couplers at 620nm. I believe that I was the first to put TE coolers, and automate a dye pump system (according to Bob Yazell of Coherent in the early 90s). I designed the system with a linear stepper motor to close the splash guard, start the pump under control, establish and maintain steady pressure, open the jet, and then open the splash guard. The TE coolers were also under control to maintain temperature. I also used a thermos-like container for the dye with quick connect hose fittings for dye pump, dye return and vent. The dye return line was designed to allow the return dye to gently flow bak to the container to eliminate bubbles. Any bubbles will destroy the output including dye overheating and can spray into the enclosure which is a mess to clean. Old hemostats and folded paper towels come in handy to get the majority of the mess prior to final cleaning with methanol. I ran these with the laservideo projectors until 2000. There is a picture on the bottom of the page on my site at: http://laservideo.com/profxand.htm with a pic of the system with a 599OEM dye laser running and a 171 argon pumping the dye and also providing the green and blue beams.

The Coherent adjustment procedures were not completely correct as if you disassembled the 599 and then put everything back by the instructions you would have some parts left over as I found during a trip to Japan in 1992. It is what I termed DYe Laser Hell The documentation is mostly correct, but in regards to the dye jet holder, remember this was designed by engineers so a good starting point is for everything to be adjusted fairly uniform (evenly) for all the adjustment screws, I may have some additional Coherent procedures that are not in the standard documents. I will have to hunt for them.

It is also important that the dye jet be completely clean. If you see a twisting of the jet as it reaches the catcher tube, there may be some dried dye at the end of the jet. Ultrasonic cleaners with methanol worked for me and if there was something that would not take care of, I would use a single strand of thin copper wire with hemostats and gently dislodge and particles from the jet.

I used R6G exclusively and I also used COT as a triplet quencher. It really stinks and the smell does not go away for years, but it will give you around 30% more output than without.

Good Luck!

laservideo

[jonsinger]

Jonsinger,
Just to review, what drive laser are you using? Never having even seen a dye jet laser I'm curious about the turn on/turn off process. Isn't there a lot of spray at that time? I wonder about the shape of the free component of the jet. If not plane parallel, doesn't it act as an active maybe even dynamic optical element? The fact these things obviously do work fascinates me. Good luck!

Hi.

1) The drive laser I'm _trying_ to use is a 200-mW green DPSSL module. (I have seen one publication where the authors managed to threshold R6G with ~70 mW out of a similar device, so I have at least a small amount of hope. OTOH, I may have to go get some "real" R6G. The stuff I have here is trash. It lases nicely under flashlamp pumping, and I've even lased it with a nitrogen laser on a few occasions; but it is basically junk.)

2) I should photograph the innards of the CR-599; there can be some spray when the circulator starts pushing dye to the jet, but they've been rather clever about it. First off, you turn on the circulator and let it develop a bit of pressure. Second, when you flip the switch from "Pump" to "Jet", it has a nice solenoid, so it starts up very abruptly. Third, there's a little silicone rubber shield that slides back and forth; when you are about to start the thing up, you move it so it covers the jet area where the beams are. This minimizes the chance of liquid getting splashed onto the optics. Once the jet is flying, you move it away so it doesn't interfere.

3) The shape of the free component of the jet is The Magic -- it's what allows these things to work. The very first few CW dye lasers used actual cells, and they were just wacko. (The dye solution has to move through the pumped region very quickly, and it's beastly hard to make that happen when it is in contact with any surfaces.)

4) They do, indeed work. Sometimes. If the stars are in the right places in the sky, and Murphy is momentarily distracted.... Seriously, though, I'm hoping that I can get this one to go. I've swapped out the regular OC for one that appears to have at least 99% R around 590, which should help bring the threshold down; and I've been trying to optimize the pump beam focus, ditto likewise. Unfortunately, so far I've been unable to bring the pump up to the pressure that's called for in the doc, and that may be a show-stopper until I get my hands on the proper tubing to take the dye back to the circulator. (There was only a very short stub on the laser when we got it. I could swear that I've seen similar tubing someplace, but I can't recall where, and it isn't anything I've seen at the hardware store.... argh.)

Cheers --
jon

[lls@laservideo.com]

I probably have everything that you need, but it will be at least Monday before I can try to locate things. Will reply again then.

laservideo

[jonsinger]

I probably have everything that you need, but it will be at least Monday before I can try to locate things. Will reply again then.

laservideo

Outstanding! I have a hurricane to deal with until then anyway. ;o) ...or maybe #

Best --
jon