I'm doing an undergraduate research project, part of which requires me to build an extended cavity diode laser (ECDL). The new diode mounts take receive the diode in a 90 degree rotation of the old ones, so the polarization is rotated. My mentor says that we need to find a work around for this, since the direction of the polarization of the laser light will effect the efficiency of the diffraction, but I can't seem to find material that explains this. I've found a paper that mentions the fact that the polarization has more or less feedback depending on whether or not it's parallel or perpendicular to the grating lines, but I can't find any explanation further than that. Can someone explain this effect?
Paper referenced: http://www.moglabs.com/uploads/2/4/2/1/24212474/manual_ecd_rev4.20.pdf section 3.3