Dichro Adjustment

[gottaluvlasers]

WOW-

REAAAAALLY good info here! thanks everyone! i talked to adam also, and he kinda "dumbed it down" for me.

Thanks everyone for the advice. "CDBEAM" i sent ya a PM.

i will be re-attempting this over the weekend. so, be forewarned- i will be posting many, "OH GOD, PLEASE HELP ME" threads!! lol.

-Marc

[LASERGUY]

Hey Marc

I am still a little new here and still have not chimed in on a discussion yet.
I figure my first post may as well be to help someone out =)

Attached are some two "shaky" camera photos of my setup.

I have chose one laser to be my reference beam (The Argon)...

The red and green lasers travel paralell and are each steared with adjustable mirrors.

Having this extra mirror adjust provides me the extra degree's of freedom to walk the beam around to be indicent with the blue spot on dichorics.
The ensures I have near field alignment right at the dichorics.

Then I simply look on the screen (far field) and ajust the dichroric mounts to overlap the spots... Once again only referencing to the "reference" laser (blue argon)

When these spots are on top of each other I have both near and far field alignment..
The result is 3 perfectly superimposed laser beams..

Hope this helps a little..

You guys rock!

[allthatwhichis]

That is an interesting looking set up. Don't drink any cofee for a day or two and take a few more pics. I'd like to see it nice and clear. How are you blanking the argon?

He's right about the reference beam. Mine is my maxyz. I actually align my green and blue to the red separatly, overlaping them first on the dichro by adjusting the height and positioning of the lasers themselves. Red to galvo mirror center and the green to center of the red spot on the dichro, then align the green to the center of the red spot on the galvo mirror using the dichro adjustment knobs. If your near field is good your spot on the wall should be aligned. Then I turn the green off and repeat those steps with the blue laser and tweak it all in making sure they're all tightly matched by checking the box of the test pattern.

[chad]

He is using scan blanking for the Argon line. See the thing just to th left of the argon. It is a little hard to make out but it looks like he has two mirrors mounted 90 to each other doing a retro bounce off of a prism.

He also has three rotary solenoids for safety shutters, nice and legit.

Must be fun to tune the blanking with the fast diodes and the slow scanner.

Looks good.

Chad

[LASERGUY]

When I have a chance I will take some more photos of my setup (With a tripod)

Chad hit it right on the nose... I am using a galvo for blanking (The poor mans blanking setup) Some time back I won a AOM off ebay but I am missing all the unique cables.
I will try to work on this again sometime in the next month. In the mean time this blanking hasn't been to aweful. Considering I am still using very slow scanners I think that my diode lasers are blanking to fast.

I would love to go with a solid state blue laser but there is a strange romance with the old school Argon I will always have. I just can't give it up. (Is that wierd?)

[andy_con]

heres mines

[LASERGUY]

Andy,

Nice work on those homemade kinematic mounts!!

If you don't mind, I might reference those for when I build my beam box and terrets =)

[andy_con]

http://www.laser-man.co.uk/2006/inde...id=34&Itemid=6

[gottaluvlasers]

LASERGUY-

thanks for the chime in! you have quite a different set up than im used to seeing and now you got me thinking! DAMN IT!!!! lol...

using mirrors to help with alignment seems (i may be WAAAY wrong...) to make more sense. rather than relying on perfect measurements and optics mounting. at least with adjustable mirrors, AND adjustable dichros youre giving yourself more opportunity to "dial in" your perfect alignment.

laser guy, andy and others-

do you think that the loss through the optics using, in essence, 2 or 3 extra reflections, will be noticeable? laserguy- did you find it easier to align with the mirrors? or do you think you would have done just fine if you used the standard (most setups here anyway)-

green shooting through......red next at 90 degrees and blue last at 90 degrees??

...very curious right now.....

oh, by the way- laserguy, GORGEOUS projector! damn right you keep the argon FOREVER!!!
whats the total combined power output of your projector?

-Marc

[LASERGUY]

Hey Marc

I definitely think having the extra mirror adjust is the way to go...
It simply makes things easier to dial in quickly without loosening base bolts or platforms of the lasers. I do alot of small educational shows in the schools... I may only have an hour to set up and its nice to quickly tune up the projector with ease.

The losses on each mirror are definately something to consider.. 2 - 4% loss per mirror.
This is why I chose my weakest line (Blue from the argon) to be the reference beam. The blue laser only suffers losses through the dichorics. The red and blue (more powerful lasers) are the laser lines I allow to suffer the losses of extra mirror bounces.

You can combine the lasers anyway you choose... As long as you are using the appropriate conbination of dichorics.
The first dichoric is a 45 degree green reflect (Blue tranmit)
The second dichoric is a 45 degree red reflect (Blue and Green transmit)

My projector puts out approximately 500mW.. Losses are inevitable and you just have to accept them. Or just get bigger more powerful lasers =)

P.S. - Thanks for the praises... ever since I came on board here I have been a little humbeled by the the other users equipment. There are some serious setups here.
Makes me feel good that someone appreciates my work =) Thanks dude!