Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Question(s) about the 593.5/589nm process

ZRaffleticket

ZRaffleticket

0
Joined
Feb 4, 2010
Messages
3,280
Points
113
Yeah either will produce it-- however 589nm handles it better than YVO4

593.5nm can't be made with Nd:YAG. The 1342nm line is too weak in that I think
 





ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
Ok, so it is the other way around. Thx. I always forget. Alot of times in good quality ones I'm told the yvo4s are used alot more in many DPSS systems because they are typically better for most applications but the YAG still has a few it's better at, and I believe are slightly cheaper to produce.
 
Last edited:
crazyspaz

crazyspaz

0
Joined
Jul 4, 2012
Messages
2,834
Points
63
it sure would be fun/P.I.T.A. to try to make a 589 DPSS lab type build. the real problem i see it trying to perfectly combine two IR beams. who knows, maybe i will wake up tomorrow and be able to see IR. hope not though :D
 
ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
crazyspaz said:
it sure would be fun/P.I.T.A. to try to make a 589 DPSS lab type build. the real problem i see it trying to perfectly combine two IR beams. who knows, maybe i will wake up tomorrow and be able to see IR. hope not though :D
Click to expand...

I considered this. But it's not so easy to get the materials...and I can't afford the crystals to simply try it for fun. Anyone wanna donate a broken yellow? :p

Also if you want a hot tip for doing dpss, use a guide laser. Use a stable low power laser like a hene and use it to align the basic setup before you start, then tweak it to get it lasing properly with the diode you're using, then tweak the wavelength and make the fine adjustments. I'm sure bloom would be a good resource on this, and can tell you just how hard it is.
 
Last edited:
hwang21

hwang21

0
Joined
Mar 27, 2013
Messages
2,416
Points
63
That makes it hard to imagine exactly how china manages to produce thousands of cheap greenies...
 
ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
probably lower quality crystals, and not necessarily at an optimal alignment? hence the +/- 10nm written on the stickers. and yellows use different crystals and of a higher purity/quality.
 
hwang21

hwang21

0
Joined
Mar 27, 2013
Messages
2,416
Points
63
Well no for the DPSS process to work it has to be pretty precise... any DPSS green working properly will be around 531.58nm
 
crazyspaz

crazyspaz

0
Joined
Jul 4, 2012
Messages
2,834
Points
63
ultimatekaiser said:
I considered this. But it's not so easy to get the materials...and I can't afford the crystals to simply try it for fun. Anyone wanna donate a broken yellow? :p

Also if you want a hot tip for doing dpss, use a guide laser. Use a stable low power laser like a hene and use it to align the basic setup before you start, then tweak it to get it lasing properly with the diode you're using, then tweak the wavelength and make the fine adjustments. I'm sure bloom would be a good resource on this, and can tell you just how hard it is.
Click to expand...

good idea. i may attempt it in the future. probably not anytime soon (due to material cost), and probably not handheld. i see CNI sells the necessary crystals, i imagine they would sell higher purity crystals than what you fan find on ebay. but who knows? personally, i think building a 589nm of any kind-lab handheld, whatever- would be a very rewarding accomplishment.
 
ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
It's nearly impossible. You'd need special equipment to do it. A guide, special eye protection, the materials and lots of time. It's not as simple as poking them around and seeing if you can get it to spit yellow. Even a "simple" green is fairly difficult to do well. If you want to learn I'd start there first.
 
Last edited:
ZRaffleticket

ZRaffleticket

0
Joined
Feb 4, 2010
Messages
3,280
Points
113
yeah.. you're likely not going to see any yellow at all.

The thing about people home-building 532's from bare parts is that the crystals like to lase at 532nm. 589nm is just not quite as simple as putting this in front of that and poof pretty light like 532nm is.
 
ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
even 532 can be fairly difficult to produce, and it's by far the easiest alignment to make as the 1064 line is very dominant over the others. its time consuming however, especially if you don't know what you're doing. though honestly you get better at it with practice. you just need a steady hand and good eye protection. I have to say a naked dpss makes a pretty light show though....no question about that.
 
Last edited:
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
I think it's worth clarifying some terms being used here... might confuse newcomers.

SHG is second harmonic generation. That is frequency doubling.

SFG is sum frequency generation. That is combination of photons at any two wavelengths to create a photon of the new wavelength / frequency.

What may not be clear from reading this thread is that SHG is SFG - it's just a "special" case that combines photons of the same wavelength / frequency. Third harmonic generation (frequency tripling) is also simply a special case of sum frequency generation.

The whole process is driven by the idea that a photon's frequency is proportional to its energy; combine two photons - thus combining their energies - and you get a brand new photon of a new energy and frequency.

In any case, the input beams are phase-matched in the doubling medium, and the collision of the photons yields the new photons of your desired wavelength.

Trevor
 
Last edited:
bloompyle

bloompyle

2
Joined
Apr 26, 2010
Messages
4,175
Points
83
Well I have no tried to align a DPSS, I have used a guide laser for other things.

Last night I had to use a 543nm to shine it through my OMNI 532 tunable, and then tune to that wavelength, and align it to the source laser. Sounds easy right?

So the laser must first fire through the OC, then go to the intra-cavity prism, then onto the OC, and back to the HeNe, perfectly aligned. NOT FUN.

Like creating an external-cavity within 3 lasers at once...Given that each side of the Omni 532 has an X and a Y screw, and a screw that shouldn't be touched.

Not fun ;)

Keep in mind that once you line up the guide beam, you're then taking it out, and replacing it with a a diode module.

This will not be an accurate transition. The module will not be in the same position as the guide laser, so using this method will actually not be very helpful, given that the variable will all change once the lasers are swapped out.

This will NOT be a fun project.
 
crazyspaz

crazyspaz

0
Joined
Jul 4, 2012
Messages
2,834
Points
63
wouldnt be fun/easy/quick. but sure would be cool. like i said, wont happen in the near future.
 
ultimatekaiser

ultimatekaiser

0
Joined
Mar 10, 2013
Messages
2,918
Points
113
Indeed this is not a walk in the park. It's a very complex matter for photonics experts. I've personally did a few larger greens at one point, but they were quite gaudy. One of these days ill try to make a smaller neater one though... And @bloompyle.....yes i bet that is indeed a pain in the ass, we have a double Brewster tube I used in class until someone thought it wa funny to mess around with the mirror alignment. Took forever to fix....
 
Last edited:
You must log in or register to reply here.




Top