| 摘要 |
<p>If the optical isolator at the input of optical telecommunication systems with fibre-optical amplifiers is omitted for cost reasons and because of the impairment of the noise characteristics caused by the insertion loss, a strong pulse can be emitted at the input when an optical plug-in connector is opened. To avoid this, a monitoring device (7) is used which rapidly disconnects the current of the pumping laser (4) or interrupts the optical path of the pumping laser (4) when the input power of the fibre-optical amplifier (4, 5, 3, 6) drops below a certain threshold. <IMAGE></p> |
