| 摘要 |
An optical fibre amplifier with automatic gain control comprises a length of doped optical fibre 1 having a signal input optical fibre 2, a signal output optical fibre 4, a pump laser input optical fibre 3, a pump laser 5, sampling means 6 that samples the level of the signal on the signal output fibre 4, and a control unit 11 that controls the drive current to the pump laser 5 to compensate for variations in the output signal level. The sampling means 6 includes a mandrel and waveguide (7, 8 Fig 2) for tapping light out of the output signal fibre 4, The optical fibre may be erbium doped, and the signal input may be amplitude modulated. <IMAGE> |
