combine beams with diffraction grating?

[wondertwnz]

Recently happened across a few articles on this. has anyone tried to use a diffraction grating to combine beams. from what I read you basically align the lasers to hit a single spot but the beam from each has to hit at a exact angle to match the diffraction angles.

Someone with a lot more knowledge please chime in
Larry

[laser_freak]

I'm only using my limited optical knowledge about diffraction gratings, but I don't think this is possible for combining 2 different wavelengths. The angle of the laser beam after the diffraction grating depends on the wavelength of the laser. I also don't think this is possible for combining the same wavelength lasers because they would have different angles of "approach" to the diffraction grating which would also change the output angle.

Hope this helps

[tocket]

It is possible to combine beams of different wavelengths with this technique, but the efficiency is low. The light entering the grating will be spread over several diffraction orders and you can only combine them in one of the peaks. You will only get decent efficiency if you have a grating that diffracts all light into a single peak.

A better way would be using a refractive element such as a prism.