Combining RGB DPSS

[illuzion]

Ok as for the order of the lasers, that is the configuration I have, if you read earilier posts, it says one filter has to pass green and reflect red, This implies the green is the farthest from the scanners. The other filter passes Red+Green and reflects blue, that would put the blue laser closest to the scanners. Also due to blues worse beam quality and higher divergence, I figured to do this in order to keep the beam spot small when it hits the scanners and keep the blue optical path short as possible. Here is the funny reason I asked the question I did earlier. Edmund's "top of the line as per everyone here" dichros are the 45Degree units NT47-266, NT47-267, and NT47-268, in the 25mm variety they sell at $45.00 each. Edmunds 532nm 25mm mirror is triple that price, and their broadband mirror is $95.00 in 25mm, since my optic mounts accept 25mm round optics, I would prefer to get something precut instead of epoxying them in to the mount. So from what I gather dichro is cheaper than mirror in this case. I'm sure I can get a cheaper mirror elsewhere, but I really can't be bothered, I really don't care a whole lot about loss on green, after all I have about 1.1W to spare, damage threshold may be a concern though for cheap mirrors.

[JimBo]

Why not do as I suggested and not bother with a mirror/dichro for the green, just have the green pointing direct at the galvos.
That way it costs $0

Jim

[yaddatrance]

To add one thing to this discussion, dichroism has two valid definitions in the optics world. Both are correct, but are referring to two different things.

The one which is relevant at hand is filtering colors (wavelengths), the second is filtering polarizations (Polaroid technology)...

Bridge is talking about the latter form of dichroism, where you can see significant power loss due to the absorption of the power into the medium if your polarisation is off. You can tell because he is talking about the P-plane and S-plane ratios.

It is also known that you can see a bit of both in dichroics depending on the manufacture process. But for the purposes of laser entertainment, we mainly buy polarization-insensitive dichromatic optics.

That edmund's mirror is a dielectric, to realize why its expensive, imagine a dichro coated enough times to reflect all wavelengths. The reason to buy that mirror is if you're using a laser >1W. Aluminum front surface mirrors will
ablate (and thereby stop being mirrors) at relatively small power densities.

As an aside, we were at the grand opening of the Revolution Lounge in Vegas on valentine's day. (Though technically, you could go in and see the place around December) They had 35,000 REAL!!! 3"x3" dichroic mirrors there! When they were building the lounge, they called Rosco and bought all of their seconds! Their claim to fame is those interactive tables you saw on youtube.

[illuzion]

My original design had the green aiming right at the galvos, but I opted for a more compact design, and using a kinematic mount I could achieve better alignment than moving a 1W laser around, so instead I went with a 90degree approach. shrinks optical deck to 12"x12" (I happen to have nice scraps of thick 6061 aluminum that size), after all I am trying to improve upon my previous projector (a 6' long aluminum deck with 2 60x heads on it AR/KR, beam table, etc).