| 摘要 |
<p>The appts. for amplifying an optical input signal includes an amplifier comprising a first input for receiving the optical input signal, and an output for providing an amplified optical output signal. An optical fibre is coupled between the first input and the output, and a pump device provides and couples an amplification optical signal to the optical fibre. A second input receives an amplification control signal, and an electrical output provides a signal indicative of the signal provided by the pump. The amplified optical output signal changes w.r.t. the optical input signal and the amplification control signal. Control circuitry receives the electrical signal, produces the amplification control signal, which is limited to prevent the amplification optical signal from exceeding a fixed threshold value if the electrical signal indicative of amplification optical reaches a predetermined value and regardless of a decrease in the optical input signal during the first instance.</p> |
