| 摘要 |
<p>Communication is established between two relatively rotatable elements having an axis of rotation 6 along two concentric light paths passing between the elements. Holographic elements 2, 2A, 3, 3A, 5, 5A are used to form light from input fibres 1 and 4 into these concentric light paths and to collect light onto fibres 1A and 4A. <IMAGE></p> |
