Help..PLS..Can't mix green and red

[blrock]

Hi,

I've got a problem. Now that I have 500mw 635nm red I''ve been trying to mix it with my 1watt green. I don't have a professional mount for my dichroic so I made my own one. I've tried for 5 hours already and I just can't get the red perfectly inline with the green.

Both beams hit the XY scanners perfectly but they about 30cm part on a wall 2 meters away.

I don't know what to do

 

[kiyoukan]

with what ever laser you have shining threw the optic mark a dot on the wall at around 20-30ft away then turn it off and try to get the other laser on that same dot.
Also make sure the beams are hitting at the same point on the optical glass. that is your first step.

 

[HIMNL9]

Basically, your error is, probably, that you try to align the beams on the scanning mirrors ..... you need to align the dots for the maximum possible distance BEFORE to direct them on the mirrors .....

Try this:

1) align the beams on the dichro, in the way that both the beams hit the dichro on the same point

2) now, without move the lasers, align the dichro in the way that, at the maximum possible distance where you can point the beams, they become overlapped, and block also the dichro.

At this point, you must have a beam correctly aligned for point it on the scanning mirrors.

 

[Cyparagon]

This thread is useless without pictures.

 

[blrock]

Thanks for the reply...yes I have been trying to align them on the scanners. So I must align on dichoic first. OK. I'll try tomorrow and post some pics.

Thanks again

 

[HIMNL9]

Just for explain better what i meant:

Also, if you have a long room and a piece of FS mirror, you can do a better work with the long distance alignment ..... place the assembly on one side of the room, and the FS mirror on the other, in the way that it reflect the beams on the wall, near you ..... this double the distance that the beam have to travel, and for the optic lever principle, also the displacement of the beams when they are not aligned ..... and also, in this way, you have the dots near you, for check better if they are aligned moving the dichro (it's not easy to look at 10 or 12 meters for check it, or have to continuously go back and forth ..... and, more is the distance that the beam do, more precise is the final alignment )

 

[chipdouglas]

what kind of mixing are you going to get with half the amount of red than green. i thought you need like more than 4x's the amount of red than green?


michael

 

[Benm]

I suppose the bottom diagram shows it very clearly: the spots need to overlap on the reflective side of the dichro if you want any chance of getting it right at all distances.

If they do not overlap exactly, you can adjust to get the beams to mix at one distance only. That may be on the scanner mirror, or even a meter away from the scanner mirrors, but never for all distances.

 

[blrock]

A big thank you to all the help. Your advice worked!

I removed the scanners and first aligned them on the dichoic. It took a bit of time but all went well. Now I have 1.5 watt Yellow Well more like green/yellow.

I got a nasty blister on my hand when I took the picture with the beam shining on my hand.

Herewith some pics

 

[kiyoukan]

Learned not to do that again i hope,
Good job glad to see you got every thing working.
interesting idea on how you aligned the beams btw.

 

[Things]

You dont need as much 635nm red to match a high power green as it's closer to the eye's peak sensitivity. I have a 200mW green and a 200mW 640nm red in my scanner and that gives a yellow with a slight green tinge .. it depends on your definition of "yellow"

 

[Asherz]

Could you not try and drop the power slightly on the green? If you have access to the insides?

 

[blrock]

The green laser does have analog modulation. So I can drop the power. I've just got all the guts out my case so once I assemble everything again I will drop the green power slightly.

 

[chipdouglas]

thats awesome you were able to align the beams... and your pic with the yellow hitting your hand is nice... keep up the good work man


michael

 

[Flaminpyro]

Realy was there nothing around you could pick up to do the same thing with instead of using your hand, do you realize how stupid that looks :tsk:
I would have been ashamed to even say anything !

I got a nasty blister on my hand when I took the picture with the beam shining on my hand.

 

[Benm]

Right.. shining a 1 watt 532 onto your hand is a bad idea... thats why they invented class-IV (i.e. 'will set stuff on fire'). Red light goes fairly deep into your tissues so gets spread out a bit more, but the green will cause a (superficial) burn.

As for the power ratios and color mixing: you'd need about 3 times more 635 than 532 to make both lasers appear equally bright... but there is a whole range between orange and lime for different ratios that might still be visually pleasing to look at!