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O-like Crystal

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A tiny review about Susie's Crystal :

http://www.o-like.com/b2b_cplist.asp?catid=467
i bought the "High end Optical Crystal GKTP " one and the "Laser Crystal YVO4-331 (applied to <300mW)"
They were well packaged as usual and fast shipped

In the picture, a typical KTP and Nd:YVO4 crystal from a newish green pointer to show the size comparison.

I don't have time now to make some test with a pump, but sure i will complete this thread later

:beer:
 

diachi

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That KTP is pretty big.:eek:

Are the crystals coated for 808>1064>532 , or are they uncoated ? At that price I may need to get a set for myself , looking forward to test results.


Regards,

Adam
 

Xer0

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what did it cost? i imagine to use a smaller one as a seed for growing own ktp's...
 

diachi

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You say that as if it's hard :D You can slap the crystals into a metal heat sink, then just fire some 808 through them and you should get some green, Granted it won't be stable or anything. I've made green with the crystals sitting on my desk and then firing 1W of 808nm at them. No mounts or anything, made over 100mW of green.

Regards,

Adam
 

GooeyGus

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You say that as if it's hard :D You can slap the crystals into a metal heat sink, then just fire some 808 through them and you should get some green, Granted it won't be stable or anything. I've made green with the crystals sitting on my desk and then firing 1W of 808nm at them. No mounts or anything, made over 100mW of green.

Regards,

Adam
Not so much with these crystals. You need an output coupler and a precision mount to align it, just like any cavity.

Did you purchase an output coupler coated for AR 532 and HR 1064? Should be a plano concave lens with an ROC of ~50-100mm. If you dont have one of these, you're not going to get any green light until you get one (in fact, you wont get any light except some pump light :D )

Also, is the back if your nd:yvo4 coated to be the HR mirror? In other words, these are the minimal coatings you will need, if you dont have them (you probably do, but just in case....) you will need an HR mirror. Here's what you should (and most likely do) have:

Side one (facing the diode) HT: 808nm HR: 1064nm, 532nm (when it catches the light just right, it should reflect GREEN)

Side two (faces the KTP) AR: 1064nm


Welcome to the world of 'more complicated than a DPM crystal DIY DPSS'. You will be very happy when you finally see a spark of green come out!! It's tough and requires a lot of patience and good mounts/design, but its worth it in the end.
 
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Benm

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I've made green with the crystals sitting on my desk and then firing 1W of 808nm at them.
With 2 separate crystals, or with a vandate/ktp assemby already in one piece?
 
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soz, i won't do any test until one month (still at University). But im sure i will get good result with the cmount or 9mm 2W from Heruur (check ebid.net and Group buy section here).
i ordered a couple of defective labby unit from aixiz (their 50mW-80mW version); planning to remove the little crystal and get the other optic for final collimation.

Here is some specification for the crystal (you won't find better deal for the Nd:YVO4, but some possibility for the KTP (heruur have few one at low price, bigger, but not new):
YVO4-331 (applied to <300mW) [price:$30] (o-like won't have the Laser Crystal YVO4-332 (applied to >300mW) [price:$48] anymore in stock, the difference is the Nd percent : 1%, versus 2% for YVO4-331.

Laser Crystal YVO4-331 (applied to <300mW) 30$
Both sides are coated .
S1:HT@808nm HR @1064nm
S2:AR@1064nm ar @532nm
Dimension is 3*3*1mm Nd percent is 2%.

Note on percentage of Nd : the higher mean not necessarily the better =), there is higher absorption and the crystal need more heatsinking.

from :http://books.google.fr/books?id=RK3...-yJDQ&sa=X&oi=book_result&ct=result&resnum=10

High end Optical Crystal GKTP (Applied to >200mW) 36$
Dimension :2*2*5mm
AR Coated

i also bought OC&HR mirror on ebay :

This auction is for 2 pcs of mirrors (1 HR & 1 OC) for DPSS YAG Lasers.
Specifications
  • Both plano mirrors
  • Both diameter 20mm
  • Both thickness 5mm
  • For the HR (Rear Mirror, High Reflection), at 1064nm, R>99%
  • For the OC (Output Coupler, partical transmission), at 1064nm, T=20%
  • Material: K9 Glass, can afford high energy laser > 200W
  • There mirrors are coated by a local military institude with great quality
i got them for 11.5$ + 5$ shipping (ask the seller to use china post) but i see that seller won't sell them again ! price considerably raised up to 40 $! dang! was lucky
http://cgi.ebay.com/1-pair-of-laser...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
 

GooeyGus

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That OC mirror wont work.

You don't need that HR mirror since it's built into your ND:YVO4.

The OC mirror you bought wont work. It's designed for only 1064nm, not 532nm. Notice how it says 20% transmission, that is bad.

When you have a laser that only lases at 1064, your OC mirror obviously needs to let some of the 1064nm light out, which is why it has 20% transmission.

In a 532nm laser, you need 100% reflection of 1064 (or 99.9%, since nothing is perfect), so you can get a high energy density of 1064 inside the KTP crystal for frequency doubling.

Also, your OC mirror needs to be coated for AR 532, to allow the 532nm light to exit without losses.

And that OC mirror probably has a huge ROC since it's designed for high power yag lasers, not low power 532nm lasers.

I would contact CNI about getting an OC for 532 with an ROC of 50 to 100.


I suggest you start doing a LOT of reading. Sam's FAQ will help you out with this. You've got a lot to learn but it will pay off when (if) you get green.

Save that set of mirrors you bought for a high power yag setup, but you wont get anything but a whole lot of frustration of you try to use them to make this green laser.
 

Benm

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In a 532nm laser, you need 100% reflection of 1064 (or 99.9%, since nothing is perfect), so you can get a high energy density of 1064 inside the KTP crystal for frequency doubling.

Also, your OC mirror needs to be coated for AR 532, to allow the 532nm light to exit without losses.
That depends.. on wheter or not you want to do the doubling intra-cavity.

Most approaches to green dpss lasers use intra cavity doubling, but it can be done with the nlo outside the 1064 lasing cavity... something to decide upfront though!
 

GooeyGus

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That depends.. on wheter or not you want to do the doubling intra-cavity.

Most approaches to green dpss lasers use intra cavity doubling, but it can be done with the nlo outside the 1064 lasing cavity... something to decide upfront though!

Yeah but if you're building the whole thing from scratch, on a CW laser, doubling outside the cavity would be pretty silly.

Now on a pulsed laser, doubling outside the cavity is no big deal because your pulse energy will be super high anyway.

BTW, that OC looks like it will work perfectly :)
 

Benm

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I suppose that you would want the doubling to be intracavity as long as you use diode lasers as the pump really.

If that's the case, you'd be looking for mirrors with much less than 3% 1064nm transmission though, since any 1064 nm light emitted is effectively lost. In such a setup both mirrors should be HR for 1064, the rear mirror HR for 532 (and AR for 808) and the OC HT for 532.

Building a dpss requires pretty specific components though, especially if you want cw operation. If you pump the 1064 with flashlamps things change obviously since external doubling becomes feasible.
 
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IT WORKS !!! HAHAHAH IT WORKS DANGGG AMAZING IT4S UNBELIEVABLEEE !!!!!!!!!
(more picture coming soon)
 




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