Method and apparatus for beam coupling. In one example, a beam coupler includes a first beam displacer configured to receive a linearly-polarized signal seed having a first wavelength, and an unpolarized pump beam having a second wavelength, the unpolarized pump beam including first and second linear polarization components, the first beam displacer being further configured to spatially translate the first linear polarization component to co-locate the first linear polarization component with the linearly-polarized signal seed, a second beam displacer configured to spatially translate the second linear polarization component and recombine the first and second linear polarization components of the unpolarized pump beam, and to co-locate the unpolarized pump beam with the linearly polarized signal seed, and a dual-wavelength waveplate interposed between the first and second beam displacer, and configured to rotate polarizations of each of the first linear polarization component, second linear polarization component, and linearly-polarized signal seed.