Laser Alignment Help

[polishedball]

You should start with the green only make sure that it is hitting the mirror perfect, Then align near field being sure your other beams hit the dichros exact where the green does. The you tilt the dichro as needed to adjust far field.

According to the seller it only had 4 - 5 hours of use. Was very clean inside with little to no dust inside of the casing or fans.


The point where the beams hit the galvo seems very dispersed. no clear distinct point to align. Best way I could describe is muddy or cloudy. It came with the phoenix 4 controller and software along with a 50 ft ilda cable and road case. The price seemed right at 560.00 with shipping. But now I am starting to understand why they sold it.

[Brian]

I was wondering if the lens, dichro, or cubes are dirty or something is making the beams dispersed. The point where they intersect with the galvo is just not clean. looks like it has overspray around it like how a spray paint can would do.

At what point on the first galvo should I be targeting with the green? right now it is hitting very near the bottom edge.


Even though this is very frustrating I still enjoy learning. However I might be better off looking for a more friendly mount for the dichro and cubes.

You should start with the green only make sure that it is hitting the mirror perfect, Then align near field being sure your other beams hit the dichros exact where the green does. The you tilt the dichro as needed to adjust far field.

[Fenechlaser]

Best place to aim the green is so that it is half way up the mirror of the first galvo and also so that it reflects half way on the mirror above or below depending on how the galvos are set up. This is (was my setup).

Also, sseign how the laser is set up, try to see how the output from the PBS is to check if they need allignment (if they are whacked and you already said that I did not follow the post exactly all through). If you want to use your current holders/mounts, the only thing that I can say to make allignment easier is to loosen just enough that you can adjust with enough but not excessive force, and then leave a bit of 'compensation' for the travel that the mounts experience while tighting everything. Also, it can also be the case that after adding the last dichro to the equation, the green beam will be out of horizontal allignment due to refraction through the dichros (there might be up to 4 mm travel depending on dichro thickness). What I've found to be a 'guide' was to allign the green with the dichros approximately in place and at approximately at 45 degrees (as they normally are supposed to be)

Hope this helps, and do use the pdf that allthatwhichis posted, it taught me how to allign with ease.. Thanks Stanwax

[taggalucci]

Yes, make sure all of your optics are clean first. This will otherwise not be as accurate as you hope. Stanwax sells some optics cleaner that's very good.

[james]

Just a quick question.... Are you using a fogger to put something in the air so you can see the beams? I can tell you from my own experience that makes a HUGE difference! Looking at your diagram, I see you have a system that is actually quite similar to what I have. I start by getting the green to shoot right through the middle of each dichro and onto the one scanner mirror in a good position. Make sure that scans well. That is really your most dependent starting point. Once you have that, you have three targets for each of your other lasers. You align them to the green spot on each dichro, the same spot on the one galvo mirror and then the far away spot where the galvos project out onto a screen or wall. I know what you mean when it comes to tightening down the screws and moving the whole thing. That's a real pain. It's also a pain to align the dual lasers of the same colors into their PBS cubes and on through the rest of the beam path. It's useful to have a black card or something to block off one beam and then the other. Make sure you don't use anything that will burn. Be very careful. Don't wear any reflective jewelry like rings or a watch. If you can, turn the beams down as much as possible. Be patient and try to learn from and enjoy the process. It might sound weird but you will get a feel for it and then you will be an Alignment Zen Master! It takes a lot of trial and error and trying things in different orders.

[allthatwhichis]

That is defiantly a good point; smoke or fog in the beam path will allow you to look at how the beams are over lapping across a distance as opposed to just on the dichros and salvo mirrors.

[Brian]

I have discovered that one of the cubes is damaged. The side facing the laser is scared almost like it was burned or some type of coating is rubbed off. In addition the green laser is loose on the mounting base. It appears that the person that sold this adjusted everything and anything trying to align it before giving up and selling it to me. Once I stabalized the green laser and removed the cubes I was able to align fairly easy. I think I will need to shim the green laser a bit to get it up higher on the salvo mirror. I am not sure what to do about the damaged cube.

Any suggestions as to how to determin what cube to replace this with?

[polishedball]

you can get broadband PBS's from several, you may just want to post a wanted to buy, in the buy sell forum. Or you can get them from Dave, perhaps Marc at CT>

I have discovered that one of the cubes is damaged. The side facing the laser is scared almost like it was burned or some type of coating is rubbed off. In addition the green laser is loose on the mounting base. It appears that the person that sold this adjusted everything and anything trying to align it before giving up and selling it to me. Once I stabalized the green laser and removed the cubes I was able to align fairly easy. I think I will need to shim the green laser a bit to get it up higher on the salvo mirror. I am not sure what to do about the damaged cube.

Any suggestions as to how to determin what cube to replace this with?