Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Tutorials, Help & Repairs



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 12-14-2009, 07:31 PM #1
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default KTP & ND:YV04 Crystal Help Required!

Hi all,
I happened yo "aquire" a couple crystals which I'm hoping to pump into a nice green output, but due to my admitted inexperience, i'm not sure if I have the right crystals, or "exactly" what to do with them to align them into producing a visible green beam output from the 808nm 1/2 - 1 wat C-mount laser diodes I've also recently aquired.

It seems i have enough "stuff" to make something usefull, now I just have to put it all together, and I'd rather look like a moron and ask questions that "BE" a moron and ruin something!

I've "read" several tutorials, and as some of you probably know already I've postedquite a few times here asking questions, and have received alot of great help and direction, thanks for that to those that have helped me thus far!

I'm attaching a couple pics here so you can see for yourself what I've just received from Atom Optics in Asia, then maybe you can make some suggestions on how I can use these crystals to my benifit.

One of them (the ND:YV04) is marked with the letter "A", I assume to indicate an "axis" or something? Perhaps someone could explaine that to me further. The KTP crystal also seems to have a marking on it, kinda looks like an "L" maybe, not sure what it is, and the corner looks like it is nicked off or something, so I"m not sure if these crystals are even the finished product and need to be further cut and or polished before they can be used or something.

Thanks!






canpower is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 12-14-2009, 11:12 PM #2
billg519's Avatar
Class 3R Laser
 
Join Date: Feb 2008
Location: London, Ontario, CANADA
Posts: 1,056
Rep Power: 129
billg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond repute
billg519 billg519 is offline
Class 3R Laser
billg519's Avatar
 
Join Date: Feb 2008
Location: London, Ontario, CANADA
Posts: 1,056
Rep Power: 129
billg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

Do you know if these crystals have coatings? One facet of the NdYVO4 should be HT808 and HR1064, and when viewed from different angles, this coating causes an apparent color change. If your crystals are uncoated, you will need the appropriate mirror. You will need an output coupler for your laser. Can't quite tell from the photo, but is there really a big chunk broken off the end of the KTP? Hopefully there is enough left of it to use.
__________________
I have a few lasers ... (62 handhelds, 11 labbies, 7 gas lasers, and 6 LPM's) I need more ... I have lots of goggles too! Eye safety comes first!
billg519 is offline   Reply With Quote
Old 12-15-2009, 01:18 AM #3
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Hi,
Apparently the crystals are not coated, as they appear the same colour on all sides. The ND:YV04 crystal almost looks like it is coated with a somewhat metallic kinda "textured" coating, kinda bumpy looking really, the KPT doesn't look like it is coated in anything, just rather rough, no surfaces are polished like glass on either crystals.

I was wondering if these crystals could be used as is, or needed to be coated wity something, or cut and polished somehow.

What does the "A" mean that is written on 2 sides of the ND:YV04 crystal?

So what are the "appropriate mirrors" that I need? What do I need to do exactly to put these crystals to good use? Are they of value to anyone out there if there is too much work or expense involved in putting them to use?

canpower is offline   Reply With Quote
Old 12-15-2009, 02:13 AM #4
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Oh, BTW, there is a chunk taken off the one corner of the KTP crystal, it came that way, so I "assumed" it was for a reason, roughly 1/5 of the surface on the end remains untouched. Is it a problem? I'll be posting some closer up pics of the crystals if it will help you to understand what exactly I have here.
thanks
canpower is offline   Reply With Quote
Old 12-15-2009, 04:10 AM #5
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Here are a few pics of the crystals that are closer and more detailed.







canpower is offline   Reply With Quote
Old 12-16-2009, 06:51 AM #6
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

well, any suggestions anyone? I could REALLY use some advice about this!
Thanks
canpower is offline   Reply With Quote
Old 12-16-2009, 10:16 AM #7
HIMNL9's Avatar
Class 4 Laser
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
HIMNL9 HIMNL9 is offline
Class 4 Laser
HIMNL9's Avatar
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

Those looks as unfinished crystals ..... as far as i know, for use them, you need to get them optically finished AND coated ..... don't think you can use them as they are in the pics, sorry.
__________________
High Impulse Multipath Neutron Laser (mark 9 ) (LOL)
Dare mo mita koto no nai, kaze, kumo, suna, umi ..... Kokoro no hate no doko ka eien ga kagayaku.
HIMNL9 is offline   Reply With Quote
Old 12-16-2009, 05:39 PM #8
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Thanks HIMNL9 for the info, i really appreciate it!

I'm sure there must be SOMETHING that I can use these for, and if not, then if there is anyone out there who CAN make use of them, and wants them for a fair price, let me know

What about the KPT crystal shown here? Can't that at least be used after I aquire a "finished" NdYVO4 crystal? Does the KPT need to be optically polished or coated in any way?

From what I've read, the KPT need only be "smooth" enough to pass a beam internally through it without scattering the beam, as it is the material itself that causes the change in light, not a special coating, but as you know from reading this thread, I'm just learning all this stuff, (or should I say "re-learning"..lol) and I might not totally understand the purpose, role and correct usage of a KPT crystal yet.

There is just SO much information to take in out there, and I don't know about anyone else out there, but unless your a nucleay physicist, it's hard to "translate" useful info into terms that a non-scientist can readily understand. That what I think people are relying on at a place like this, fairly quick answers without having to read a textbook just to unearth one fact or a small simple answer to a question. Well, that's at least "my" case anyhow...hehe

On the upside, I've aquired a couple more crystals that I'm "sure" I can make use of, as the are definitely finished and coated, as you can see in the below pictures.

These crystals are YAG, not ND:YV04 as shown in the previous pictures, so my question now that I know the ND:YV04 are kinda "useless" to me as they are is, "how do I use the YAG crystals"?

Again, I know I'm probably asking "obvious" questions that most of you all know, so my apologies for that, I just know that if anyone out there can offer good quality and "reliable" advice, it's the people here, after sifting through all the innovative mods and creations on this site, you guys are great

I thought all my C-mount 1/2 to 1 watt infrared diodes were all 808nm in wavelength, but upon closer inspection, i realized that they are all a "mixed bag" of IR laser diodes, so I realize now that the first thing I need to do now is "classify" each diode as per it's wavelength in order to use it properly, but that's kinda difficult to do with no equipment to do so.

I think it's all guesswork from here on in, which really sucks, because I might have everything sey up properly, but then try pumping something with the wrong wavelength of light, and not know "exactly" what's wrong in my setup...lol.

I know I've probably got all the stuff to create a decent laser setup, but putting it all together is the hard part! I'm just not sure where to start now. If I "had" a "working" ND:YV04 and KPT crystals, it would just be a matter of pumping them with many diodes from my assortment of diodes until one of them produced a green beam, but not even having that makes me wonder exactly where to start!

Then at least I would "know" I really do have at least ONE 808nm diode, which I'm sure I do, I have over 60 diodes, ONE of them must be right for the job!!

I REALLY hope someone out there can help me make use of this stuff and get a system together, hope to hear from someone soon!
Thanks!!

Chris





canpower is offline   Reply With Quote
Old 12-17-2009, 08:33 AM #9
HIMNL9's Avatar
Class 4 Laser
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
HIMNL9 HIMNL9 is offline
Class 4 Laser
HIMNL9's Avatar
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

It's difficult to say you something useful only from these pics, sorry ..... anyway .....

Basically, you can have 2 different types of conversion cavities, based on these two crystals, that are coupled or glued assemblies (i mean, the crystals can be contained in a holder that couple them mechanically, or can be already matched in polarization and glued together in a single assembly)

The glued ones give you the less problems, cause all the work of matching planes is already done, you just need to push in 808nm, find the better polarization for the diode, and ZAP, green out ..... the others have usually complex coatings ..... the doubler is usually coated AR for 808nm and HR (high reflectivity) for the 1064nm on the input facem and HT (high transmissivity) for 1064nm for the output face ..... the converter is usually covered AR for 1064nm for the input face, and HT for 532nm and HR for 1064nm for the output face (some very high cost units have also HR for 808nm on the input face, but is rare)

Don't know, really, if someone at hobby level can do polishing and coating operations like these ones .....

By the way, just as idea ..... if you don't know what diode of your ones is 808nm, and if you find around a cheap (maybe also burned) 5mW green, they have inside a small glued unit that is ready for use with 808nm, and don't react to other wavelenghts ..... just get the inside crystal assembly and put it in front of your diodes (in the right sense, ofcourse), maybe also just keeping it with a plier (always work with IR protective goggles, doing these types of tests !!!) ..... if it shine out some green light, at some rotation angle, the diode is 808nm, otherwise not
__________________
High Impulse Multipath Neutron Laser (mark 9 ) (LOL)
Dare mo mita koto no nai, kaze, kumo, suna, umi ..... Kokoro no hate no doko ka eien ga kagayaku.
HIMNL9 is offline   Reply With Quote
Old 12-17-2009, 03:46 PM #10
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Hi HIMNL9 and thanks for your suggestion!
I did in fact already try doing that with a pre-glued green laser pointer crystal, and NO output at all, I posted previously asking for help about that as well, and finally gave up as I just couldn't get any green output at all.

I "assumed" I either did not have any 808nm diodes in my bag of tricks, or that I could not accurately align or turn the crystal to the right position to "polarize" it, as I understand its not just the alignment from the 808nm beam to the input of the crystal, but the crystal must be oriented in the right "rotation" to obtain a certain polarization which also is necessary to create the green beam output, is this true or not?

Regardless, I was not able to get a green beam out of any of the green laser pointer crystals I have laying about, which was depressing in and of itself, so I went on to experimenting with the crystals I had on hand to see if I could "do" anything with those.

I now know that the KTP & ND:YV04 crystals I have are just "rough" and not coated, which is needed to create a beam obviously, but what about the KPT crystal?

Does the KPT crystal also have to be polished and coated with certain wavelength coatings in order to be used, or can it be used in it's unfinished form as the one shown in my picture here? I observed a thread here sjowing a KPT crystal being pumped, and it did not "appear" to be coated or anything, but as you say, you can't tell much from appearances or pictures can you really.

I now know the specs for the Nd:YAG crystal shown in my pictures, the one that is "lense shaped" is a rough Nd:YAG, but the rod shaped one is a finished Nd:YAG crystal, and it has a coating:1064/808 double point,double anti-reflection coat, and ND concentration is 0.9 for the finished rod shaped Nd:YAG crystal.

So I'm assuming that knowing this, I just need a verified 808nm laser diode to pump it with, and then a proper KPT crystal to then convert the 1064nm into a 532nm visible green beam?

Again, does the KPY crystal need to be polished and have surface coatings applied for 1064nm input, and 532nm output in order for it to create a green beam, or is it the very nature of the KPT "material" that accomplishes this "conversion"?

One more question, probably a stupid one, but what "exactly" is the purpose of the particular type of gemstone material if it is basically just the "coatings" that do all the conversion work from one wavelength to another??

I mean I've seen glass laser rods that are coated 1064/808, so why the need for YAG material?

I've actually built flashlamp ruby rod laser cavities years and years ago from scratch, but I "assumed' that the reason this worked was because of the excitation of the chromium molecules in the ruby material laser rod, and the fully and partially reflective mirror polished ends that accomplished the "lasing" process, not a particular wavelength passing/blocking capability that produced the resulting beam output.

as I say, I'm re-learning all of this, so thanks for your patience in my asking all of these questions, eventually I'll get it all!
Thanks!!

Chris
canpower is offline   Reply With Quote
Old 12-17-2009, 04:38 PM #11
HIMNL9's Avatar
Class 4 Laser
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
HIMNL9 HIMNL9 is offline
Class 4 Laser
HIMNL9's Avatar
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

Uhm, i think you are making a bit of confusion, but no problems ..... trying to say it in poor words .....

The conversion is in the nature of the crystaline structure of the material and in their nonlinear properties, one turn 808 to 1064, and the other "double" the wavelenght from 1064 to 532 ..... the coating don't have anything to do with the bare converson, they are used for increase the efficency of the crystal cavities ..... bouncing the non-converted light again in the crystal for use also it and get more output ..... hell, my english is not so good, give me 5 minutes for draw a scheme



Edit: ok, more or less, the optimization due to the coating works in this way (but keep in mind that i made it on-the-fly and is a lot schematic, ok ?)



and i also forgot the AR for 532nm at the end, anyway, basically, an optimized cavity may have this principle of work ..... as you see, all the energy that is recovered from the various coatings, and all that what can be reflected more in absence of the AR layers, are all efficency gained ..... bare crystals may be very less efficents, wihout coatings.

About your trials, maybe you just not matched the polarization of the crystal, trying your diodes (you shined them in the right direction, right ? ..... cause pumping the crystal from the output just don't work at all)
Attached Thumbnails
KTP & ND:YV04 Crystal Help Required!-cavity-works.jpg  
__________________
High Impulse Multipath Neutron Laser (mark 9 ) (LOL)
Dare mo mita koto no nai, kaze, kumo, suna, umi ..... Kokoro no hate no doko ka eien ga kagayaku.

Last edited by HIMNL9; 12-17-2009 at 05:14 PM.
HIMNL9 is offline   Reply With Quote
Old 12-17-2009, 06:58 PM #12
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Thanks for taking the time to answer in such detail, the concepts your drawn here are basically what were in my head, except for the fact that I "assumed" that without the coatings, the conversion (doubling) just would not take place.

If you look in this thread, I was told my KTP & ND:YV04 crystals that were NOT coated would not work at all unless I had them cut, polished and coated. I actually CAN cut and polish gemstones, its something else that I do, but have no idea how to coat anything!

So without the coatings, then what would happen? Would you still get a frequency change of light output, but it would not be efficient due to the non-reflection of the lightwaves forward caused by the coatings?

If so, then just how much "loss" would you get? I guess this is why you pump with such a powerful diode, and get such little amount output compared to the power input, (like 30mw of green from a 500mw 808nm laser diode) so the coatings help correct that and boost the output power back up because of their forward reflection of light right?

I made sure the laser diodes output was pointing in the right direction, and have just been attempting to place the ND:YAG crystal or the ND:YV04 as close to the laser diode's output as possible. I realize I'm probably losing most of the beam from the diode that way, but still expected at least a bit of the laser light, (hopefully enough) to make it through the first crystal to cause a beam output from the output of the crystal.

Is there a "proper" way to couple the laser diode to the first crystal it shines into? Do I need to somehow collimate the beam from the laser diode to point on the first crystal's surface, rather than just putting the crystal up to the output of the laser diode?

I laid the KPT crystal down on an elevated flat surface (on the top surface of a very large heatsink actually) ,then placed the ND:YAG crystal behind it, and then put the laser diode's output directly up to the ND:YAG crystal's input surface (or what I hoped was the input!), then I "rotated" the round ND:YAG crystal rod clockwise observing for an output of any green from the KPT crystal, but all that was observable was the faint glow of the infrared from the laser diode making both the crystals glow internally the colour of the laser diode's output, no green output at all, other than the laser diode's original faintly visible colour, but like you said, I'm not "sure" if I am using an 808nm diode or not.

I was hoping that I just needed to "polarize" the alignment properly by turning the ND:YAG crystal until it was aligned properly, and it would work out, but clearly I'm doing something wrong, I made sure to flip the rod around end for end just in case I had it backwards, but no difference. I did the same with the KPT crystal, flipping it around end for end, just in case I had it backwards or something. As you can see, one end of the KPT crystal is missing a slight amount from it's output end, I hope this does not effect the working of it at all.

Does the KPT crystal also need to be in a special position, due to some polarization factor or something? It is rectangular, and just in case of this, I tried laying in on each one of it's 4 surfaces to see if it made a difference.

So, what am I doing wrong, or "not getting"? Is it how I'm coupling the laser diode to the first crystal (the ND:YAG)? All of the examples I've seen of making a home made "cavity" just seemed to "lay" the first crystal (the ND:yag or the ND:YV04 crystal) in front of the C-mount laser diode, then just "lay" the KPT on the other side of the ND:yag or the ND:YV04 crystal.

I "do" have a lot of 9mm can diodes as well, but wanted to use the C-mount ones as I think they are all a bit higher power, I'm under the impression that all of the diodes I have are from 1/2 to 1 watt output, (the guy I purchased them from won't EVER answer any emails, so I'm not quite sure exactly what I have, he didn't even include the couple red visible one's he promised in his auction description and won't answer my emails about that either, geesh) and if I put a peice of black electrical tape up to the output of the C-mount laser diode while power is applied to it, it immediately burns and starts to smoke alot, so I know there is a decent power coming out of the laser diode.

Thanks for you help, hope you can point me in the right direction!
canpower is offline   Reply With Quote
Old 12-18-2009, 01:24 AM #13
billg519's Avatar
Class 3R Laser
 
Join Date: Feb 2008
Location: London, Ontario, CANADA
Posts: 1,056
Rep Power: 129
billg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond repute
billg519 billg519 is offline
Class 3R Laser
billg519's Avatar
 
Join Date: Feb 2008
Location: London, Ontario, CANADA
Posts: 1,056
Rep Power: 129
billg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond reputebillg519 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

The crystals shown in your newer photographs are rough. They need at minimum to have the ends ground flat and parallel to a high degree of precision, and then the ends must be polished to optical perfection. The current rough surfaces simply scatter any light, no possibility of conversion or lasing. If the crystals are not coated, then external mirrors as detailed above are required. Have you looked over Sams Laser FAQ about how DPSS works?
__________________
I have a few lasers ... (62 handhelds, 11 labbies, 7 gas lasers, and 6 LPM's) I need more ... I have lots of goggles too! Eye safety comes first!
billg519 is offline   Reply With Quote
Old 12-18-2009, 07:59 AM #14
HIMNL9's Avatar
Class 4 Laser
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
HIMNL9 HIMNL9 is offline
Class 4 Laser
HIMNL9's Avatar
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

Well, as billg said, faces must be optically polished and finished, highly parallel and ofcourse, the faces that you have to polish are the correcy ones (yes, also the direction in which the crystal become cutted related to its internal structure is important) ..... i don't know these specific crystals, but i assume that the marked faces are the ones to utilize, and is possible (only possible, as i've said, i don't know these specific cryrstals), that this mouled "chip" on the corner, shaped as an arrow, is a marker for the light direction (but i'm perplexed about that, usually the direction marker is just printed on one of the unused faces as an arrow or a "V" indicating the direction)

About the coating, it's a bit difficult that you find any optic shop that can do them, cause normally are made with different layers of different chemical substances, depositated on the right face in a precise order with different rocesses (can be chemical deposition, or for the more expensive ones, condensation from evaporation in a vacuum chamber, and depend from the required substances)

Cheap crystals can also work with less coatings, and have a little less efficency (as example, the first can just have AR808 in front and HT1064 at out, and the second AR1064 and HR532 in front and AR532 at the output ..... guess chinese assemblies are like this )

Yes, if the light is focused at the input, the efficency is ofcourse better ..... cheap pointers have usually the crystal almost touching the diode, better ones have also a collimation lens between the diode and the crystals, for maximize the quantity of 808nm that go in ..... but for test yiur diodes, with that crystal that you said (the assembly from the pointer), can be enough just place the crystal, in the right sense, over the diode and rotate it, you cannot obtain a beam collimated without the output optics, but if the diode is 808nm and the crystal is not damaged, some graan light must come out ..... if you see nothing in any position, or the diodes are not 808nm (+/- 5nm), or the crystal is burned or broken.

By the way ..... i never cease to say this ..... are you using protective goggles for IR ? ..... and, if you want to see if your diodes are working correctly (if they lase, if the pattern of the beam is good or contain dead zones or lines, and so on), just get a cheap webcam, or also better one of those ultra-cheap "b/w microcamera" for surveillance that are selled around and an old video monitor or a TV with composite video input or scart adapter ..... our eyes cannot see IR, but these cams see it as normal light, so if you point the diode on a wall from a meter or similar, and look at the wall with the camera, you can clearly see if the emitted pattern is ok.



EDIT: also, don't pump too much power in the crystals, or you burn them, especially bare crystals without heatsink .....
__________________
High Impulse Multipath Neutron Laser (mark 9 ) (LOL)
Dare mo mita koto no nai, kaze, kumo, suna, umi ..... Kokoro no hate no doko ka eien ga kagayaku.

Last edited by HIMNL9; 12-18-2009 at 08:03 AM.
HIMNL9 is offline   Reply With Quote
Old 12-18-2009, 01:00 PM #15
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
canpower canpower is offline
Member
 
Join Date: Nov 2009
Posts: 30
Rep Power: 0
canpower can only hope to improve
Default Re: KTP & ND:YV04 Crystal Help Required!

Hi there, I keep saying that I look at the beam output via a camcorder in night mode, NOT my eyes, I need my eyes...lol.

Forget about ALL the other crystals mentioned, it's obvious they are rough and a lost cause, lets focuse on that finished and coated ND:YAG rod shaped crystal I have.

According to the manufacturer, it's ready to use as is.

I was "really" wanting to know was exactly how to couple the C-mount 808nm laser diode to it, (which you say to use a collimating lense at the output of the C-mount laser diode pointing to the input of the ND:YAG) and if I need to "rotate" that NAD:YAG crystal rod to "polarize" it somehow.

I was just not sure if rotating the ND:YAG rod was a necessary step in getting it aligned to cause a beam to come out the other end of it or not.

My next specific question was whether or not I needed a KPT with finished optics or not, I know it is not "optimum" the way it is, in the rough condition, but I was wondering if the "conversion" from 1064nm to 532nm STILL occurs EVEN though the KPT crystal is not coated and has polished ends, I recall seeing a "rough" looking KPT crystal being pumped in this forum somewhere, and it STILL had a green output.

At the very least, I have a 808nm input and 1064nm output ND:YAG crystal (the one that is ROD shaped in the pictures is a FINISHED crystal) ready to use, according to the manufacturer, it has a coating:1064/808 double point,double anti-reflection coat, and ND concentration is 0.9 for the finished rod shaped Nd:YAG crystal.

I figure at LEAST I can get the laser built to the point where I have the C-mount 808nm laser diode coupled to the ND:YAG crystal to have a 1064nm output, and "waiting" for a working KPT crystal to be added to create the 532nm output, so lets concentrate on working with what I "do" have to get it "that" far at least! Then I can "aquire a KPT crystal and complete the laser cavity later I hope.

I'm also wondering, if you reverse the ND:YAG rod, can you then input 1064nm and get 808nm out, or is it ONLY made to reflect in ONE direction?

Thanks for your help guys!!

canpower is offline   Reply With Quote
Old 12-18-2009, 02:57 PM #16
HIMNL9's Avatar
Class 4 Laser
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
HIMNL9 HIMNL9 is offline
Class 4 Laser
HIMNL9's Avatar
 
Join Date: May 2009
Location: Lost somewhere in the EU mess ;)
Posts: 5,416
Rep Power: 404
HIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond reputeHIMNL9 has a reputation beyond repute
Default Re: KTP & ND:YV04 Crystal Help Required!

Uhm, wait ..... i don't know what coating have your ND:YAG rod, so cannot say you if is a directional converter or a bare rod with AR coatings on both the ends ..... if is just AR coated, it can work in both the directions (with the correct polarization), if is a directional unit (that have AR808 and HR1064 at the input and AR1064 at the output, it ofcourse don't work well in reverse ..... do it have any "arrow" or "V" shaped mark on the external border ? ..... do you see any difference in the color reflections of the two faces, with the same light and angle ? ..... i know it's difficult, but cannot say you what i don't know

Anyway, if your rod say it's AR coated for 808nm and AR coated for 1064nm both the sides, with no HR side, then probably is a bidirectional unit ..... and, if is a big crystal, must be for use it with high input power (as example, i have a pair of cavities that hold 2x2x6mm crystals assemblies, and the original diodes was 2W C-mount with FAC and collimation lenses ..... your one looks more big, maybe can hold 5W ?) ..... And, NO, you cannot push in 1064 and get out 808, it just convert from one wavelenght to another ..... is not the direction that convert it, is the inside nonlinear atomic structure of the crystal, that make it.

Usual crystals for this use are square plates, and yes, are coated with different finishing and have a sense of work, only in one direction, cause the different coatings, not cause the direction of the light.

And, ofcourse, both the crystals must be finished and polished, for work, not just the ND one ..... i never tried to use a bare KTP for see if it work or not, i don't have unfinished ones ..... but i really doubt that it can just take the 1064 and double it "as is" ..... as far as i remember, also the orientation of the atomic structure inside the crystals, must have a precise plane, for convert the IR to green ..... i mean, when the producers cut and polish the crystals, they have to do this following precise structural orientations, otherwise, no conversion. (for this reason, also, when you get a finished crystal, it also have the indication of the direction in which the light must flow, other than for the coating)

At last, you can made some tests with the bare crystals, but if you reach to obtain a conversion and want to build something stable, you need to put the crystals in a heatsink ..... the conversion process generate heat, and a too much heat with no dissipation can easily damage your crystals ..... the small ones in pointers, as example, are not glued on a brass holder just for alignment and handling, but also for take heat from them, through the brass holder.


EDIT: found it !

You was probably referring to the unit built from mauswiesel, about the posts showing it working ..... the posts is this one ..... and here you can also see from some pics how he arranged all, for have an idea (well, sure better than with my bad english )
__________________
High Impulse Multipath Neutron Laser (mark 9 ) (LOL)
Dare mo mita koto no nai, kaze, kumo, suna, umi ..... Kokoro no hate no doko ka eien ga kagayaku.

Last edited by HIMNL9; 12-18-2009 at 02:59 PM.
HIMNL9 is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 12:58 PM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC