The Big Green Thread (I'm gonna regret posting this in the morning)

Quote:

---

BTW the major dimensions of the laser in Jon's pic are roughly 104 x 144 mm. Just knowing that does not give you anywhere near enough data to clone it.

---

Ya, that would have been my approach when I was 12. The important features will just not show up with that level of resolution.

Quote:

---

Also measuring the small electric field generated in the KTP/LBO lets us see when the doubling is peaked. Most of them are piezo materials. Learned about that trick last night. Really shows up on a Qswitched laser. Its a mV or so on a CW laser.

---

Interesting, but will that maximal stress equate to maximum conversion? It makes sense that it would equate to maximal energy focus within the crystal. As with the Laser Scopes, you max the IR and then adjust the KTP to max the beam conversion

Quote:

---

However the Qswitched pulse produced is long and weak compared to a real Qswitch in a long cavity such as ours.

---

Right. So this may be one of those areas that we can risk and just go on and test.

Quote:

---

Which leads me to the next question, doubler oven or no oven?

---

I'd vote for yes especially in a first test model. The LIUJun-hi group cooled both the rod and the KTP and designing with this feature will allow us to determine if it is a benefit. If not then eliminate it, but harder to incorporate it if "not sure if everything is OK". The "oven" can heat or cool depending on the polarity of a TEC and so I would use this as the heat source rather than a simple resistance element.

How about we build a VW bug 1st, then build the Ferarri 2nd ? :p

shoot-- posted again at the same time as planters post ..

Quote:

---

Originally Posted by mixedgas

the major dimensions...are roughly 104 x 144 mm. Just knowing that does not give you anywhere near enough data to clone it.

---

No, but, I think if someone did a 'traceover' / re-modeled in Solidwerx, etc, any minor distance / measurement-inaccuracies from lens-distortion, should-still be able to yield a fairly-decent 'model', ya? I mean, prolly in the 'ballpark', anyway...

If I was 'rolling in dough', I'd just up and buy that Gem on eBay, and 'sacrifice' it for the R&D.. at-least, for what data could-be gleaned, as, as you say, outright 'cloning' is not-cool, etc.. Besides, you just might find a 'better-path', since the LQ-design was no-doubt a 'balance' between good Green-yield, and the Manuf. costs / profit model, for *hundreds* of units.. What is the 'universe', in this project, maybe 10-20 units, right? Point-being, perhaps there may-be some more 'lux' (costly) yet, better-yield design parameters / materials, etc, once a 'basic model' is proven..

Anybody up for a 'trace-n-learn' project? Sorry, would love to help, but I can-is too-busy... :p
ciao
j

Steve-o,

I am not trying to be a smart ass and I know this sounds a little like we're on Neptune, but this is really the focus (no pun intended). A little overkill on the speculation/ design front at this point is free. I think within a very short time we will have enough worked out to order components. I am trying to aim a little high (Ferarri) so that if we come up a little short we still have a bug. Despite Steve's obvious competence, no one here has actually thrown a few of these lasers together. Once we have a better idea of what works and that is public then anyone can use this to assemble something close to what they want and they have a good chance of success.

I have built them, but only with one pump diode and a measely Watt of green, and that was with passive cooling. Balancing the amount of metal around the KTP was tricky with no TE. I ended up sliding it in and out of a heatsink. I've done that twice. Once at 30 mw, and once at 1 watt. The passive cooling range is narrow, too narrow,.
This time I'm doing it right,



Whats ticking me off is Casix is no longer publishing their standard list of stock DPSS mirrors.

All the Asian vendors used the same list. I no longer have the old printed catalog.

Wayback machine, I guess.....

Nothing less then 2 watts and a M^2 of 1.4 or less will make me happy.

I like tight beams.

Steve

Yeah I'm not trying to be a smartass either .. appeciate you and Steve's hard work that you're doing.

Waybacking, semi-complete:

This is the critical line:

Plano concave with radius of:

50, 80, 100, or 200mm

Most Chinese designs used those radius restrictions.


Casix.com, circa 1998.
Quote:

C. Diode Laser Pumped Laser Optics (R is the reflection at normal incidence)
Substrate One Surface Other Surface Part No. Price

1064 nm 808 nm 532 nm 1064 nm 532 nm

BBO KTP R<0.1% R<0.5% R<0.1% R<0.5% DPO8101 $450
KTP R<0.1%
R<0.5% R<0.1% R<0.5% DPO6101 $150
Nd:YVO4 R>99.8%
R<5% R<0.1% R<0.5% DPO6102 $250
Nd:YVO4 R<0.1%

R<0.1%
DPO3101 $190
Nd:YVO4 R>99.8% R<5% R>99% R<0.1%
DPO3102 $290
Nd:YVO4 R>99.8% R<5%
R<0.1%
DPO3103 $250
Cr:YAG R>99.8% R<5%
R=95±2%
DPO3104 $250
Nd:YAG R<0.1%

R<0.1%
DPO7205 $350Iå00
Nd:YAG R<0.1%

R<0.1%
DPO7101 $190
Nd:YAG R>99.8% R<5% R>99% R<0.1%
DPO7102 $290
Nd:YAG R>99.8% R<5%
R<0.1%
DPO7103 $250
BK7 P/P R>99.8% R<5%
R=95±2%
DPO7104 $250
BK7 P/P R>99.8% R<5%
AR@809
DPO0101 $38
BK7 P/P R>99.8% R<5% R>99% AR@809
DPO0102 $42
BK7 P/V R>99.8%
R<5%
R<0.2% DPO0103 $38
BK7 P/V R>99.8%
R<5%
R<0.2% DPO0201 $40
BK7 P/V R>99.8% R<5%
AR@809
DPO0202 $40

R>99.8% R<5% R>99% AR@809
DPO0203 $45

Note: BBO size: 3x3x7mm3

KTP size:3x3x5 mm3

Nd:YVO4: 3x3x1 mm3 (1 atm% Nd) or 3x3x0.5 mm3 (3 atm% Nd)

Nd:YAG: f3x5 mm3 (1 atm% Nd)

Cr:YAG: 3X3X1mm3 T=90% or 80% @1064nm

Plano/Plano (P/P) mirror: f10x3 mm3

Plano/Concave(P/V) mirror: f10x3 mm3 with radius of curvature: 50, 80, 100, or 200mm

*Laser optics at 946 or 1319 nm is also available upon request.

*Other size and substrate materials are available upon request.

Metal Mirror

[QUOTE=dsli_jon;245591]No, but, I think if someone did a 'traceover' / re-modeled in Solidwerx, etc, any minor distance / measurement-inaccuracies from lens-distortion, should-still be able to yield a fairly-decent 'model', ya? I mean, prolly in the 'ballpark', anyway...

All that gets us is a Sagitta for the correction lenses. Sagitta gets us a rough radius. We cant see the whole YAG/VANDATE or the full KTP/LBO.
We can't tell the radius of the rear mirror, the size of the pump diode emitters, or the OC coating. No way we could get the radius of the Asphere.

Nice model to dicuss pumping from, and the pic does help with theory/education.

Steve

Quote:

---

Originally Posted by mixedgas

All that gets us is a Sagitta for the correction lenses...

---

Acknowledged... So, who's gonna spring for a sacrificial-lamb for some real-world-data mining? :p http://www.ebay.com/itm/Laser-quantu...-/110765643149 Even if it turns-out they only populate the sci-grade 'Gems' w/ 1x pump vs 2, likely, they're the same diode, and the rest of the optics are not too-dissimilar... at least it would be a real-world 'springboard' for mining some-optics data, I'm 99%-sure the rest of the 'layout' is identical to the Excels..

...Come on, PL's Daddy Warbux, (..whoever you are.. :) you know you just wanna offer them $1500.! :p

*sigh*
j

Steve,
Help me here. The orange list, how did you do that? Anyway, What does the list represent? It seems to be a list of DPSS components with a progression of properties. What are you suggesting?

Jon,
I looked up the Gem you linked to and it seems to be a 750mw laser. If that is correct and even if that is a single vs dual diode pump then the most that design is proven to produce is 1.5W. I don't think the components will necessarily work for 2+ W and at that price that seems a little steep for the benefit.