Robs 'how to' guide for alignment

[stanwax]

I mentioned in a thread yesterday that I had done some work towards this guide so I have decided today to get my finger out of my arse and get it done.

Here it is for download in pdf format - I hope its clear and makes sense.

Rob

[andy_con]

very nice mate

i did something similar a few weeks back. very basic and needs some more work doing to do, but could be usefuk to noobs

http://www.laser-man.co.uk/2006/inde...d=58&Itemid=66

[Stuka]

On behalf of all us fellow "noobs" -

Very clear and to the point - thanks for posting!!

Randy

[buffo]

Well done, Rob! Nice write-up.

Adam

[Pitts]

Hi Rob,

Your timing is impeccable, I am doing the F@#@#g alignment now.

The green (primary straight through) went well. The blue onto the green also good ( although I wasn't expecting that slight step over as it goes through each dichro which meant I had to shift things as I ended up nearly missing the mirror) but getting that red to sit on the other two beams .... especially when its a Maxy with its own near and far field adjustments.. Insane stuff.

But hey I am learning and your efforts with this subject are greatly appreciated out here by us senior newbies ( I have rank now you know ! I am now a "senior" know nothing) ..

Many thanks

Regards

Ray
NZ

[laserLips]

I saw a diagram of somthing similar in the attachment, is that what happens...It shouldnt have much effect to my aligment anyway...

Cheers, Graham

[stanwax]

Graham
I think this image shows an exagerated effect. Yes the beam passing through the dichro will be bent slightly but it will not be by a noticable ammount - or at least I have never noticed it despite being aware of the effect.

Rob

[mliptack]

Its the same reason why a spoon looks bent when you put it in a glass of water. And yeah like Rob said, it DOES happen, there is no doubt of it there, but you don't really notice it, and besides you are moving stuff around anyway to align it, so you overcome the 1mm diffraction the dichro may have caused without really ever noticing it.

[stanwax]

I think because its a negligable and hardly noticable effect it is rarely if ever mentioned - so well done Graham for bringing that up!

Rob

[Pitts]

HI guys ..

Interesting comments.

The reason I had to shift things is because I wanted the "final" combined beam to be in that sweet spot right in the center of the mirror.
I am using the Edmunds dichro's, seem quite thick I presume that is normal.
However the beam "steps over" probably a mm or so for each dichro it passes through.

If like me you wish to stay right in the centre you need to allow for this.
Say two - three mm total shift one way (after two dichro's) on a mirror that is say 8mm long is quite a percentage shift. This may or may not matter depending on what you want.

I did notice that the glueing of these mirrors at times leaves a bit to be desired sush that glue residue is evident on the mirror at the shaft end... another reason to stay in the middle.

The reason for mentioning it was to simply state this exists.(which was unexpected for me being a newbie)

Anyway a small change in the Galvo position and it was back in the middle where I wanted it.

Cheers

Ray