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574nm 36 mW Yellow Laser

kecked

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Sorry you all read that wrong. Someone said they were putting in an order and I just meant they better send me mine before they take new orders. I have not heard from freeman in three months at all....vaporware as far as I’m concerned for now till they figure the damn crystal thing out. Necsel was my best hope for yellow and that’s a bust too. Who needs two rows of 32 beams! I just need one. 100mw would be plenty.
 



paul1598419

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I heard back from my email and they said the new units are still not stable. They start out at 17 mW and drop to 9 mW in short order. I simply asked again to let me know when any stable units are available again.
 

trinh hong phuoc

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It seems they are still having trouble finding crystals,Paul,you are right ,they will need more time,maybe a year,this problems doesn't slove in a month or some months
I also wait 600nm diode
 

paul1598419

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I'm afraid you have a long wait for a 600nm diode. You can get a 605nm SHG laser for about $2500. But, a direct diode has not even been produced yet.
 

CurtisOliver

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It doesn’t change anything really, but 600nm diodes do exist. Room temperature diodes were constructed with a range of 599-605nm. I remember sharing a small thread about them a while back.
 

LSRFAQ

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Looks like some one might have known a bit in advance. From a paper I'm trying to obtain, I quote:

"However the Yb:xxx laser displays a slow degradation in power over the …"

I cant get the whole paper yet.

Steve
 

RedCowboy

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Looks like some one might have known a bit in advance. From a paper I'm trying to obtain, I quote:

"However the Yb:xxx laser displays a slow degradation in power over the …"

I cant get the whole paper yet.

Steve
That explains a lot, such as

( 1 ) Why they were so cheap.
( 2 ) Why they had a mismatched driver
( 3 ) Why they are not making more as fast as they can because I know they have buyers asking for them.
 

CDBEAM777

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Hmmmm….hmmmm...so...even the Big Time R & D boyz...have an issue....with power degradation with this crystal set-up ????????
And...their budget is likely HUGE !!! So Sad !!!

Sounds like..." Not ready for Prime Time " yet !!!! Ahhhh...I wanted 555nm @ 1W anyway !!! HAHAhahahaha !! CDB
 

LSRFAQ

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if your willing to kiss goodbye 565 to 575 from YB:SVAP (yep, I had it right long ago) and just go for the greens, then these YB based crystals are close to commercial use. However they need 2x to 4x the pump power vs a ND:vanadate green system at 532...

However if your willing to pay 100$ a meter and by ten meters of fiber with a 20 watt pump diode. ... Well there is something coming for yellow.
 

CDBEAM777

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Yikes....me head is spinn'in !!!63434

I am still reading the paper...THANX.... I can understand some....and this is not a real technical paper.....chock fulla math !!!
Well....Are they experimenting with around 555nm ????

My combiner build is nearing completion !!! Color is perceived to be approx. 555nm....But....we know the mind is mixin the lines !!! I really do not care !!! Looks Lime Green to me...…...at the " Lime Green " perceived color....

100% power output of the 532nm line = 500mW.....about 40% of the 637nm line = approx. 360 mW....so...860mW !! Looks very bright....due the influence of the green 532 OEM !!! I am happy !!

Thanx for the info....and humbling sorte !!

CDBEAM

Added note....I can get a real nice yellow from my combination unit...Very Golden....with the Red LD all the way up...I believe the Red +Green mW is above 1300mW....gotta check....maybe not so high....MMmmmm ?? at least 1200mW !!! Ra the Sun God would be proud !!
 
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paul1598419

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I read the entire PDF and it is obvious that English isn't the writer's first language. But, I am still dubious that this crystal is Yb:SVAP. In fact, the paper didn't mention this crystal at all. It was an interesting read when you finally get through it all for the information on growing these very high temperature crystals and the problems they encounter in doing so. I found the fact that these are nonhygroscopic in nature to be telling as well.
 

LSRFAQ

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I have the later papers in front of me, so I have a bit of advantage. SVAP is the only published material so far that has the full 46 nm tunable range we see on these devices, with the 565/575 yellow. and the occasional flash of short wavelength green during warmup on mine is at the other end of the tuning range.

SVAP is the one that dies slowly, but the IEEE web site is still messed up regarding accessing the relevaent paper, so I cannot see what the mechanism is.

Look at the date on the DTIC mil link. It is very early in the career of YB, which really has just sprung on the market in the past 5-6 years.

The point is these crystals need X-ray orienting before cutting and coating so they will both lase and frequency double. The yield loss during production will be large because of this. They are also a three level laser, and lasing in the IR where "yellow" occurs depopulates the lower level often, so they tend to jump around in wavelength, resulting in power instability. This makes this a tricky device to make as a thin monolithic laser. BTW< The tolerance on the pump diode laser wavelength is tight for this class of materials, about +/- 1.5 nanometers around 796 or your not lasing well.

In a laser with a large thick crystal, and external optics, this material would probably be fine. It does have the disadvantage of being strongly adsorptive at the pump wavelength, making very long crystals impractical unless you side pump.

Remember, once this crystal is cut, your stuck with what you have. This is not like a dual crystal laser ( ND:Vandate + KTP), where you can change the angle or temperature of the doubler for peak power. Ie No angle tuning for best power, and a very limited range, if at all, for temperature tuning.

Steve
 
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