| 摘要 |
<p>A beam combiner 104 for a Raman pump unit, the combiner being configured to receive and propagate at least two orthogonally polarized collimated light beams 118 and 120. The beam combiner comprises a birefringent prism 104b and an optically isotropic prism 104a. Each of the prisms is located in the path of the beams and configured so that the beams are substantially parallel to each other when they emanate from the beam combiner. The birefringent prism may be spaced apart from or abut the isotropic prism. An optical assembly 100 including the beam combiner may have gradient index lenses 102 and 110, polarization independent isolator 106 and a depolarizer 108. The depolarizer may be a birefringent prism where the optical path length of the depolarizing birefringent prism varies across a diameter of each of the beams emanated from the beam combiner. The birefringent depolarizer may be spaced apart from or abut the beam combiner.</p> |
