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Request for EXOTIC DPSS Equipment




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First one is a high reflector @ 45 degrees. So I guess it could be useful in a ring cavity, or an L/Z-Fold. Like a bounce mirror I guess. Though not useful for a linear cavity.

That being said, all 488nm DPSS is done via direct-doubling. So the only possible use is via a ring, or possibly an L/Z-Fold. So it could be useful. They've been up for several months now. I may get a pair or two at some point.

As for the second mirror, I have no idea what I'd use that for. 99.7%R@594/632.8nm. I mean, it could be a useful HR in a 594nm system. Though it says nothing about the reflectance at 1319nm or 1064nm. The two other VERY important lines. 1064nm gain is high, but 1319nm is low. So you need a very special balance of reflectance for each to get proper wavelength mixing in your KTP, or other similar nonlinear optic. Otherwise you'll just end up with a lot of green, or less likely, a lot of red. Though 594nm is also a HeNe line. So it could also be a broadband HeNe HR or OC. I will investigate further.

Consider this a bump for this thread :)
 
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Sigurthr

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Looks like a good broadband HR to me, did you ever get a 2B tube, Bloomie?
 
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Looks like a good broadband HR to me, did you ever get a 2B tube, Bloomie?

I did not. If I am ever presented with the opportunity to play with a B-Tube, I likely will, though.

However, my current interests are starting to sway towards solid state.

As I think about that, I am almost .. saddened. It was not long ago when my only desire in the world was to grab a 1-B and build a tunable laser. Or DIY some other monsterous construction.

Like the cavity dumped QCW 2kHz 25-50W broadband HeNe. Boy that was a fun concept to play with. Just wish I had the budget for it..
 

Sigurthr

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I do hope you continue gas work. I've long been hoping you get a DIY HeHg/HeSe/CVL or some other rare metal vapor laser going.

I've kind of lost interest in DPSS work, the frequency/wavelength spread is just too limited.
 
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Oh don't get me wrong, as do I. While I was at SELEM, I snagged 5 optics for $20. 2 CVL HR's, one for 578, and the other for 511 (I could tell by the tint it gave the overhead light's reflection). The other 3 were CVL OC windows. I grabbed them as I knew it will happen someday.

Though a dorm is not the suitable place for a DIY gas laser and vacuum chamber, etc. Just not the place. I really would love to attempt one still. And I still have my contacts, and I remember my designs and plans. I also still, for the most part, remember the key details about them. I'd need freshing up of course. Now is just not the time to begin one. Nor is it remotely the location.




Is it weird to suddenly change mediums like this? I mean, it wasn't overnight or anything. It just managed to take place as I poked around DPSS more. I realized that there wasn't much I could do in the gas regime, in the visible domain, without spending a lot more money on very expensive optics. Like the tunable. A 1-B is $450+, and the littrow prism would have been custom made, likely not cheap. At least $150+. That's $600 right there if I am lucky. The cavity dumped laser? Oh goodness... The Pockel Cell alone would cost upwards of 3-4 times that to get a custom built one with brewster windows for 632.8nm, add another $1-1.5k for the driver. After that, the PBS and HR would be chump change in comparison. Likely <$250 for the combo. That's about $3k on the cheap side.

Wonderful idea? Yes. Possible for me? Not for a long time, if ever.

Still, is it weird to just jump to a totally different medium? I guess it'd be different if I went from HeNe to HeCd to Ar, then Kr, etc. Though this is a totally different ball game.

Just curious I guess. Also a bit longing. There were other things I wanted to do in the gas world ... I just don't have the pockets for them all. Plus it got to the point where every new project required a whole new slew of parts, just for one thing. Started getting ... not worth it.

Thoughts?
 

Sigurthr

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Totally understand the financial aspects. I've had to reassign my efforts many times because of it. It's funny how depressing having dreams/aspirations can be when you're essentially broke. Add in the fact that I think most of our goals are academic and in addition to the enjoyment factor would greatly enhance our understanding you get a second level of depression when we think about how we might never know the answers because we cannot afford to try what we want to. The hard part is using those feeling to fuel yourself into an ever-forward momentum. It certainly isn't weird to have to make a course correction, sometimes even a 90deg one. Just don't make any >90deg, or you'll start losing ground.

You know, it is funny you mention the cavity dump laser. I had an idea many moons ago for a MECHANICAL cavity dump setup, that circumvents the expensive pockel cell and control electronics. I thought about a rotary encoder disc and having something similar machined so that it could be connected to a 10,000RPM dremel motor or such. Instead of slots on a disc, have carefully spaced miniature mirror mounts, each containing a HR. The hard part would but cutting/finding HR mirrors so that there is no third state where a nonreflective surface would enter into the cavity and thus rob the cavity of the energy. Experimental for sure, I haven't heard of anyone trying it, but I couldn't see why it wouldn't work if properly constructed either.

Dorm rules could very well be a project killer, but dorm size doesn't have to be. My office is only 12' x 10', and if you subtract all my electronics and storage sections the active work area is only 6' x 4'. I'm currently glassworking 4' x 1" pyrex tubes into electrodeless discharge tubes for use with Tesla coils and other HF-HVAC devices. My vacuum pump isn't good enough for lasers and thermionic tubes but it was only $40 used on ebay, so I only get down to 50Torr.
 
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Totally understand the financial aspects. I've had to reassign my efforts many times because of it. It's funny how depressing having dreams/aspirations can be when you're essentially broke. Add in the fact that I think most of our goals are academic and in addition to the enjoyment factor would greatly enhance our understanding you get a second level of depression when we think about how we might never know the answers because we cannot afford to try what we want to. The hard part is using those feeling to fuel yourself into an ever-forward momentum. It certainly isn't weird to have to make a course correction, sometimes even a 90deg one. Just don't make any >90deg, or you'll start losing ground.

You know, it is funny you mention the cavity dump laser. I had an idea many moons ago for a MECHANICAL cavity dump setup, that circumvents the expensive pockel cell and control electronics. I thought about a rotary encoder disc and having something similar machined so that it could be connected to a 10,000RPM dremel motor or such. Instead of slots on a disc, have carefully spaced miniature mirror mounts, each containing a HR. The hard part would but cutting/finding HR mirrors so that there is no third state where a nonreflective surface would enter into the cavity and thus rob the cavity of the energy. Experimental for sure, I haven't heard of anyone trying it, but I couldn't see why it wouldn't work if properly constructed either.

Dorm rules could very well be a project killer, but dorm size doesn't have to be. My office is only 12' x 10', and if you subtract all my electronics and storage sections the active work area is only 6' x 4'. I'm currently glassworking 4' x 1" pyrex tubes into electrodeless discharge tubes for use with Tesla coils and other HF-HVAC devices. My vacuum pump isn't good enough for lasers and thermionic tubes but it was only $40 used on ebay, so I only get down to 50Torr.

Still doing lasers of course. Just a new medium that I can start fresh with without breaking the bank.

I was thinking of the same thing a little bit ago. Using a design to an optical chopper, but have 90% of the wheel be a parabolic mirror. The trick is balancing the mirror coverage to dump sace ration, as well as rotation speed to allow for enough gain, and enough time to dump, without loosing too much light during the transition. You will lose light no matter what the quality of the mirror is. The light output would be more in the form of a wide pulse. As the output will increase as more of the beam path is allowed to be released. In slow motion, as the mirror ends, it will be like a moon calendar. A sliver, then eventually the full beam, then back to a sliver. Rather than one Gaussian spot. Worth looking into I guess.

I don't have the typical rules. I can get randomly inspected for dorm cleanliness. Not your college dorm you see ;) I've got to have everything neat, clean, tidy, and dusted. Building/filling is tube is not really a quick and clean overnight process. Then alignment while the tube is still hooked up, as it'd have to be a flowing gas system. Sure if I assembled everything, and took a couple weeks off from work, I could do it no problem. Still cost and all that. Space, etc.

It'll happen one day, trust me. HeHg will likely be the first "unique" tube done.
 

Sigurthr

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Gotcha. Ya those dorm rules suck, heh.

Aye, glad to see my idea wasn't so far fetched. Indeed the dump would be gradual (moon phases), but that is the nature of it. No event is truly instantaneous (barring quantum mechanical events like virtual particles and entanglements).

Back to DPSS. If you're going to give it a go, why not try for something a bit more unusual instead of the common 473/488/532/561/589/593.5? Give tripled and quadrupled YAG a go. Or that NLO crystal that gets pumped by 450nm (name escapes me at the moment).
 
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Gotcha. Ya those dorm rules suck, heh.

Aye, glad to see my idea wasn't so far fetched. Indeed the dump would be gradual (moon phases), but that is the nature of it. No event is truly instantaneous (barring quantum mechanical events like virtual particles and entanglements).

Back to DPSS. If you're going to give it a go, why not try for something a bit more unusual instead of the common 473/488/532/561/589/593.5? Give tripled and quadrupled YAG a go. Or that NLO crystal that gets pumped by 450nm (name escapes me at the moment).

Possible maybe. Far-fetched? Absolutely!!!

For DPSS, I am currently messing with 532 to get my feet wet. Just to learn how the optics behave, how the cavity behaves under certain conditions, etc. Just learning the basics right now.

I currently have a diode (~1-1.5W) w/ TEC. TEC in undriven at the moment. Once I get some power resistors, I can add a load to the 5V rail of a computer PSU, and use that PSU to drive a TEC driver, etc. It's a process.

Anyway. Diode, TEC, collimating lens to get a nice spot on the Vanadate. Then the YVO4, 3x3x5mm KTP, and an 50mm RoC OC.

All have the proper AR/HR coatings for 532, 808, and 1064nm. It's currently all mounted on my rail with a tiny baby HeNe for my guide laser.

Once I get the TEC driver, I can really get cookin. Then it's optimization from there. Better Vanadate mount, REAL diode mount, and a decent KTP mount with temp control.

After that, who knows. I have 3x3x5mm KTPs for 561 and 593.5 as well. Just no mirrors. Though I'm a sucker for cyan, so 488 is on the to-do list. As is 561nm as it's a nice fun color. I want to grab parts and do everything I can with them, before moving on. So I could try grabbing an Nd:YLF and doubling the 1047 for 523.5, or grab some Yb:YAG or something to double 1030 for 515. Lots of possibilities. Eventually I want to narrow down the 490-500's. That's one of my two "shot spots". The other is 600-610nm. This is possible with Pr:YLF and Pr:pAYAC (pumped with 444nm ;)) This can get me 604 and 607nm.

Though anything but 532 and 473 is expensive. Especially the 488-500 region. VERY expensive. It also involves direct doubling, so a ring cavity or something.

All in due time. Right now, my goal is to get 1064nm to lase stably :p
 

Sigurthr

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Ah, yes, that's it Pr:pAYAC. Always makes me think of Pripyat, hehe. 604/7 are beautiful. I once saw a commercial unit running in the tens of mW... purdy as hell. Price tag was insane though.

When I did diy 1064/532 a long time ago I used a MCA so I didn't have to worry about alignment very much. It was pretty much a matter of sticking it in front of an 808 that was temp regulated and rotating it until polarization was correct. I didn't have mounts so once I got some nice green flashes I called it good. I think I still have that mca sitting on a shelf somewhere if ya want it.
 
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KVANT sells 100mW 607nm for $2900.

I own a composite crystal. Yeah, drop it in front of 808nm and you're set.

Now I'm doing a "real" linear cavity.

Anyway, I'm off for the night. I'll send you my skype if you ever use it.
 
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