| 摘要 |
<p>An optical fiber collimator includes a transparent rod (6) having a diameter large compared with the core diameter of the fiber (1) but small compared with the lens (2). A first fusion splice (7)connects the optical fiber (1) to one end of the transparent rod (6) and a second fusion splice (8) connects the second end of the rod (6) to the lens (2). The first fusion splice (7) is thus relatively small and can be made with good precision (in particular, the mode field at the splice position can be kept closely circular and its diameter accurately controlled); the second fusion splice (8) does not require such high precision because its diameter is large compared with the mode field diameter at its position, and so does not affect it, nor the mode field in the light path beyond the preformed component. The invention is especially useful for collimators of large diameter, such as are used (for example) with some types of optical switch.</p> |
