| 摘要 |
The system for detection of anomalies in optical fibre co-operates with a fibre (1) which transmits a focussed beam applied via a lens (3) to the input face (10) of the fibre. To detect an anomaly within the fibre, a detector (4) is situated near to the input surface of the fibre. This may consist of a photocell detector producing a signal in proportion to the incident light intensity. The light received is that reflected from an anomaly within the material of the fibre. To improve the sensitivity of the detector a converging reflector may be arranged around the axis of the fibre just outside the fibre input surface. This reflector has a central aperture for entry of the laser beam, and collects the returned laser light in order to focus this light on to the detector. The detector may be sensitive to a wavelength of light which is situated lower in the spectrum than that normally transmitted by the fibre. |
