Is it possible to have a 2x1 wave guide combiner which doesn't through away 3dB??? Hello, I was wondering if someone knew if it was physically possible to have a 2x1 optical wave guide combiner which doesn't throw away half of the light. The light must be "single wavelength" and is unpolarised, at least initially. I've drawn a schematic of what I mean. If anyone can give me their experiences on this sort of thing I would be much appreciative. Thank you.