Large 532nm laser project

[Exerd]

I would someday like to take on the project of building of building a powerful 532nm laser. By powerful, I mean closer to 1.5W of 532nm output. It would be a bench/lab laser.

I could spend roughly $1000 on the laser. Less would be better.

I have seen many forms of mounting possibilities for all of the parts and optical assemblies. You could say that I have spent too much time attached to Thor's giant catalog. Realistically, a laser built from Thor's parts would send me on my way to the homeless shelter. Another source of setup parts would need to be found. That is what creates some of the questions.

What form of assembly mounting method would be recommended for the parts? By that I mean that I have seen items such as pegboard, cages and etc, and wondered what I may want to look towards for keeping the price down. (I do have access to a manual mill if some parts could be made by me that would not require extensive machining.)

One thing that I would like to say is that I would not mind spending more to allow the use of X/Y/Z axis adjustment on a holder for the crystal.

I was hoping for a little guidance from someone experienced in this area of building. Any tips on how to plan for this properly would be great.

Any help at all is much appreciated.

 

[Greenmechanic]

Combining module beams, if you have access to a mill should be no problem. All parts for alignment can be made easily with a manual mill. (if you have a lot of practice)
Pegboard is no where near sturdy enough. Find a AL. plate and drill out the holes you need. From there, make the X-Y-Z holders, to insert into the plate. One type for the modules and one for the beam combiners/optics. Make the tolerances slightly loose, then use set screws for the final alignment.
Good Luck!

 

[Prototype]

ND:YVO4 KTP 808nm 532nm GREEN LASER CAVITY AND LENS KIT - eBay (item 170502255207 end time Jul-18-10 17:32:42 PDT)

For the crystals. I was recommended larger mounts for the crystals for higher pump powers, but I don't remember how big, it's been about six months. Good luck with whatever way you decide to go.

 

[hakzaw1]

I had great luck finding odd pieces of AL plate, right angles, tube, channel, rod, etc at a local Al fab shop. Offerd to pay as the guy as he saves his leftovers and takes them in to a scrap place from time to time.

When I told him what I wanted them for he not only refused my $ but cut them up for me on his chop saw...nice guy. Easy stuff to drill- just keep dripping a little oil on your bits and go slow--great advice from GreenM-- he knows his stuff- made me some great heatsinks- I would rep him but the system will not allow atm(hint hint)

 

[Exerd]

Thanks for the info, guys.

A special thanks for linking that crystal assembly. I put it on my watch list. That is something which could really help. I wish I knew where to find packages like this at will. Doesn't anyone sell crystal packages like this regularly?

One other question, what exactly is an 'output coupler'? He mentions that it includes one in an aluminum housing.

About the pegboard. I was referring to aluminum pegboard. Thor sells a lot of pegboard setups for building lasers. They are somewhat expensive, but look like really nice setups for their mounts. They offer some really nice lens holders, and I would be tempted to use some because of how clean they look.

I'm probably going to piece this together slowly. I may start with the mount and the holders, and maybe add the crystal and diode last as I determine what I want to match together.

 

[Prototype]

An output coupler takes the beam output from the crystals and (I think) and shapes this into a more manageable beam for the final collimation lens.

 

[hakzaw1]

PegBoard X2™
brushed aluminum

21.5" x 45.5"X 3/4 "
1/2 ton Load Rating

$49
SPECIAL! Qty Ship/ea $14


Brushed Aluminum Metal PegBoard Panel | Peg Board Testimonials
This could be cut up to make several projects--nice 3/4 inch thick- on sale half price !! i want some!!!!

 

[Exerd]

Hakzaw, damn, that's nice stuff!

I'm hitting the Thor catalog. I'm going to try figuring out what optics XYZ holders I need to buy and maybe get that pegboard ordered. That's a deal to me.

Edit: I just realized it is boxed. I saw that it said 3/4" thick, and assumed that it was aluminum plate that thick! Whoops. Still looks nice, but I wouldn't mind having some stuff that was solid aluminum and maybe 1/2" thick. The extra weight would be nice.

 

[hakzaw1]

I thought it was that thick too-maybe you can get a free piece of thick plate and use a pegboard as a guide to drill 1/4" holes on 1" centers.
Or make your own low-budget optical table.

Do you think any of the leftovers from the Casio projectors can be used in your project?? the array HS plate can hold 5.6 can diodes up to 24 of them and there is a FS mirror thingy--

-ps just got call from UPS- my second A-130 is coming today--harvest tonite!!! Second time around SHOULD be much easier!!!

 

[Exerd]

Combining module beams, if you have access to a mill should be no problem. All parts for alignment can be made easily with a manual mill. (if you have a lot of practice)
Pegboard is no where near sturdy enough. Find a AL. plate and drill out the holes you need. From there, make the X-Y-Z holders, to insert into the plate. One type for the modules and one for the beam combiners/optics. Make the tolerances slightly loose, then use set screws for the final alignment.
Good Luck!

Thinking more about this, do you think the effort put into combining 6 modules would be worth it?

If I wanted 1 watt, I would have to combine around 6 modules, since they usually do around 150mW.

I would imagine that if I pumped that crystal set, it wouldn't be too much more money to use a single pump and optics. I would also expect the beam quality to be better if done this way, because it's focused as one output instead of 5.

 

[Exerd]

Some more questions came up today while thinking about XY translators which I may purchase.

I'm trying to figure out if I would need to buy one or two translators, since I am considering purchasing the listed crystal set with separated crystals.

I know that when working with a set of 532nm DPSS crystals, the crystal set needs to be moved around so that the optimal emitting portion of the crystal can be found. However, since the specific set listed has individual crystals that are not bonded, a question arises.

Which crystal is particularly sensitive to the pump input position? Is it the Nd:YVO4, KTP, or both?

If both crystals are particularly position-sensitive, then it looks like I will need to purchase two translators. If only one is sensitive, than I can simply center mount one, and XY translate the other to save money.

Here is another question. At what point in the pump cavity does the emission become single mode? This always confused me. I know that the crystal medium lases to form somewhat of its own output, but I always wondered why the output does not replicate the input light characteristics with some consistency. In other words, I never really understood how multimode diode light in a bar shape exits the crystal in a round shape.

 

[Exerd]

I just landed a complete cavity kit that produced over 600mW of green, with the diode, sinks, and lens, for $85. Now that is what I'm talking about. :san:

 

[Daedronus]

ahh, you need to add pictures, nice find!

 

[BShanahan14rulz]

Some more questions came up today while thinking about XY translators which I may purchase.

I'm trying to figure out if I would need to buy one or two translators, since I am considering purchasing the listed crystal set with separated crystals.

I know that when working with a set of 532nm DPSS crystals, the crystal set needs to be moved around so that the optimal emitting portion of the crystal can be found. However, since the specific set listed has individual crystals that are not bonded, a question arises.

Which crystal is particularly sensitive to the pump input position? Is it the Nd:YVO4, KTP, or both?

If both crystals are particularly position-sensitive, then it looks like I will need to purchase two translators. If only one is sensitive, than I can simply center mount one, and XY translate the other to save money.

Here is another question. At what point in the pump cavity does the emission become single mode? This always confused me. I know that the crystal medium lases to form somewhat of its own output, but I always wondered why the output does not replicate the input light characteristics with some consistency. In other words, I never really understood how multimode diode light in a bar shape exits the crystal in a round shape.

I know everyone says this, but the info is in the laserfaq. I seem to remember that the ktp should be like, 42.5 degrees off axis from the yag. Or SOMETHING is 42 or 43 degrees.

As far as how the diode output becomes round, I believe the yag or yvo is what is actually creating the laser emission. Since the 808 is in bar shape, the ktp won't halve it, but the 1064 emission from the yag/yvo would be a tem00 beam, and that does get wavelength-halved.

I'd probably get the crystals last too. Who knows, they might drop in price as time goes.

 

[Daedronus]

I know everyone says this, but the info is in the laserfaq. I seem to remember that the ktp should be like, 42.5 degrees off axis from the yag. Or SOMETHING is 42 or 43 degrees.

As far as how the diode output becomes round, I believe the yag or yvo is what is actually creating the laser emission. Since the 808 is in bar shape, the ktp won't halve it, but the 1064 emission from the yag/yvo would be a tem00 beam, and that does get wavelength-halved.

I'd probably get the crystals last too. Who knows, they might drop in price as time goes.

A good 808nm beam is also important. The tem00 1064nm beam inside the nd:yvo4 is very small in diameter and ideally you want all the 808nm pump beam to be focused and absorbed inside the same volume. 808nm absorbed outside the tem00 volume can generate extra modes or simply be wasted.

This is why fancy 532nm lasers usually have corrective optics to make the 808nm round, this allows the best possible focusing inside the nd:yvo4.