Dave;
The beam path will depend on how you plan to combine them. If you're going to use two separate dichros, then you'll have a beam path that looks something like this:
Code:
R B
| |
G--\----\----W-----S
|
O
Where R, G, and B are your Red, Green, and Blue lasers. The two '\' symbols are your dichros. the W is the resultant white light beam. The S is your scanner set, and the O is the output beam.
If you use a trichro to combine your lasers, then your beam path will look like this:
Code:
R G B
\ | /
\ | /
\ | /
\|/
T
|
|
W
|
|
S-----O
The only new symbol is the T, which represents the trichro. The other symbols are the same as the drawing above. Note that the angles will be slightly different from the crude 45 degrees to either side of the green that you see above. Here's what a trichro looks like when it's lined up correctly.
Note also that you can change the order of the lasers in the first layout (the one that uses dichros instead of the trichro), so long as you have the correct dichros. (ie: you could have the red one first, and the green one last if you wanted.) But remember that blue photons are the most expensive, and the red ones are the next most expensive. Green is cheap, so it makes sense to put it at the begining of the path, knowing that you'll loose more green since it will pass through two dichros on the way to the scanner. Putting the red in the middle means it has to pass through just one dichro, and the blue at the end just needs to reflect off (as opposed to pass through) one dichro, so it will suffer the least loss.
Any of that make sense? (I know - it's late...)
Adam