1w Green kit!! Need help assembling URGENTLY!!!!

So I bought this kit off ebay, says 1000mw kit with instructions for assembly and powering. Kit is packaged very well, including finger condoms and esd wristband, but alas....NO INSTRUCTIONS other than a single line that reads; "Adjust the distance between lens #1 and lens #2 to achieve desired focal length".

Here's what the kit includes;
(2) 1000mw 808nm diodes
808nm AR coated focusing lens set
Nd:YVO4+KTP Crystal full optics set (tiny crystal in brass housing)
532nm AR coated focusing lens

I powered 1 diode with a small driver from another laser kit and got a small red light in the tip of the diode, like a teenie tiny led inside it. I am assuming thats what the 808nm should do(?). Now how do I make it green??? I have the lenses and crystal mounted in little plastic stands that allow me to slide them closer or father apart, but I have no idea of how far apart they should be to start, and I cant see a beam to focus or align into or out of the crystal.
PLEASE HELP!:yabbem:

Contact the Seller for more assembly instuctions...
How about a link to the eBay Item you bought..





BTW...
to the Forum...


Jerry

Welcome to LPF

I am not a DPSS expert, but I can help a bit until others do. To "see" the 808nM-light, try a web-cam, or your cell-phone-camera.
Your "crystal" is actually two-crystals bonded together, you will want to use the 808-focusing-lens to focus the 808-light onto the Nd:YVO4-side of your crystal-set. I beleive the "beam-waist" should be just inside of the first-crystal. The output-coupler may just be a coating on the output-side of your KTP-crystal or it could be a seperate-piece.

I am sure you already know this, but 1W of IR can be dangerous, especially with you working very closely with the componets while trying to align things, you should really have protective-glasses.

BTW, with a 1000mW (1W) 808nM-diode you will be lucky to produce 200mW of 532nM-green-laser. If you bought a "1000mW Green-kit" this seams a little misleading, what is the second-diode for, a spare?

Hope this help a little,
Barry

Hi,

If this is your first experience with any DIY laser work, it's not going to be particularly enjoyable... Building and aligning a DPSS laser is not an easy job and requires some experience and a lot of patience.

As Dark_Horse stated, the title "1000mW green-kit" is very misleading as the process of converting 808nm light to 532nm is not very efficient.

As far as my knowledge with DPSS lasers go, it's pretty similar to what Dark_horse said, focus the 808nm light, run it through the crystal which then uses the IR laser to pump out green light, this is then focused using the appropriate lens for 532nm light.

Goodluck putting it all together, if you don't have any luck contact some more experienced members who would be a lot more help.

You may also need to check the correct voltage and mA to feed the pump IR diode so that you do not under or over power it That may be worth contacting the seller and asking about. Also a link to the kit you bought would be very helpful.

There is no way that 2 diodes even combined is going to produce 1W of green light. Nor is a BONDED crystal set (crystals that are glued together.) going to be able to produce that high of powered green. As laserbee has indicated, it's impossible for us to even advise you without seeing what it is your working with or a link to the auction. Provide those and we'll be happy to help you however we can.

That tiny little LED light you are seeing could easily be 1W of 808nm. DO NOT look into it. I advise that you get some 808nm proctive goggles.

You will want to focus the pump (808nm) diode onto one end of the crystals in the brass housing (If you look at the crystals you may see a little line which is closer to one end than the other, focus the pump into that end ). You'll know you've got it right when you see green. Then you can work on collimating the green beam from there, use your expanding lens right up against the crystals then slide your other lens further and closer until it's collimated. You're going to want your diode and crystals in a nice heatsink, they will heat up fast at 1W of pump power.

Hope that helped. DPSS isn't easy .

I really like lasersbee's smiles

Wow, the response times here are great. I thank you all for your valuable input, my only regret is, yup, I looked at the red light a couple times. I found the listing number for the auction, and also a second auction that I purchased yesterday that I would like to have assesed. (basically, was it a good buy, and is there anything otherwise special about it.)

I think the green is a bit over my head still, and I'm thinking I should probably outsource it for the build?

Thank you again for your input.

1 last question;
I terminated 2 405's in as many weeks, both were 250mw kits from Bandtled on ebay. I built the drivers as per the instruction and was measuring across the 1ohm resistor trying to determine the threshold, and both of them terminated at less than 60ma. The instructions said ma would equal the mw. Were they not correctly rated? or?

here are the auctions for green and new one, the last # is for the diode from bandtled but not the driver kit as he has no more items listed.

110437282508
170397706843
170394006009

Again, Thank you.

Oh geez, don't look at that red light. It can cause permanent blindness. You're looking at 200x the power of a "safe" Class 3a laser. In fact, if it burned out already and is just an LED now, maybe it just saved your eyes.

The "250mW bluray" kits are probably a bit overrated in power. Unless you get a freak diode, driving these to 250mW as seen on a thermal LPM such as a Laserbee (excellent meter) will result in a short diode life. You are probably better off getting a GGW or '210 from a respected forum seller and getting a lavadrive, rkcstr, or making a DDL with 317 or 1117. Drive you diode at or at least near the forum-recommended levels in order to get good life.

The "1000mW" is as stated only the power of the drive diode. DO NOT LOOK AT THIS RADIATION DIRECTLY! (sorry about the all caps - for emphasis!) 1W is very eye dangerous. You should have IR goggles for 808nm to do assembly work on DPSS, observe the diode output, and adjust the lens using a camcorder to observe the IR safely. This is a challenging build! You may have to rotate the IR drive diode to get the polarization of the IR right for the crystal set to produce optimum green. An LPM is very useful to find the optimum positioning for the diode, crystal set, and any lenses. Try to find and look over the thread where another member here photographed experiments with a drive diode and crystal set. It can be done, but most of us here just get an o-like module for green and put it into a host. To make a permenent build from the kit, you will need to be able to mount everything so it stays in precise alignment and also is heatsinked well. This can involve a little machining of custom brass parts. I would be surprised if this kit can produce more than 200mW of green at best. Are the diodes in your kit 9mm or 5.6mm. If they are 5.6mm (TO-18) they will not likely be 1W diodes. The TO-18's are usually 200mW or 500mW pulsed max.

5v1i5v0 said:

1 last question;
I terminated 2 405's in as many weeks, both were 250mw kits from Bandtled on ebay. I built the drivers as per the instruction and was measuring across the 1ohm resistor trying to determine the threshold, and both of them terminated at less than 60ma. The instructions said ma would equal the mw. Were they not correctly rated? or?


Again, Thank you.

Click to expand...

Did you short the capacitor on the driver before attaching the LD?

5v1i5v0 said:

The instructions said ma would equal the mw. Were they not correctly rated? or?

Click to expand...

That can be used as a very rough assesment of a violet lasers output, but its best just to meter it as your choice of collimating lens can greatly affect performance.

diachi said:

Did you short the capacitor on the driver before attaching the LD?

Click to expand...

Indeed. I shorted it with a screwdriver several times, just to make sure make sure I did. I had both of them running, a week apart respectively. When I went to measure across the resistor, it would only register a few Ma. As instructed, I turned the pot up slowly. It took quite a few turns before it would get brighter, but still showed very little Ma. I eventually turned and measured my way up to 55-60 ma. Turned it another 1/4 turn and got a very anti-climactic blink, dead, at just about the same point for each LD. :banghead::banghead::banghead:
The second time actually resulted in a hole through my door, oddly enough shaped just like the pliers that had flown through it only moments before when the LD went quiet.

5v1i5v0 said:

The second time actually resulted in a hole through my door, oddly enough shaped just like the pliers that had flown through it only moments before when the LD went quiet.

Click to expand...

I see what ya did there :evil:

:knight:
I MADE GREEN!


It worked! With the info you guys gave me, I MADE my first green laser. I still have quite a bit of tweaking and tuning to do, and a fading diode crappy driver issue to overcome, but IT WORKED!
I will post some pics as soon as I get it tidied up a bit, and find my camera. Thank you all again for your valued input.:bowdown:

:lasergun:

Sam's Laser FAQ - Home-Built Diode Pumped Solid State (DPSS) Laser

See this section of SAM'S FAQ LASER QUESTIONS. There are also other sections with diagrams & other helpful info. that can aid you in the final tweaking & aligning..........rob