| 摘要 |
<p>Achromatic optical retarder wherein, in use, an incident beam of light consecutively passes a first (AB), a second (DE) and a third (GH) trajectory- through birefringent material (2,4), wherein a fast axis of the birefringent material (4) at the second trajectory is oriented at a different angle with respect to a polarisation orientation of the beam of light than a fast axis of the birefringent material (2) at the first and/or third trajectory, wherein at least two of said trajectories (AB, GH) extend with a single element (2) of birefringent material.</p> |
