| 摘要 |
<p>An optical test apparatus includes an optical time domain reflectometer (1) for launching light pulses into a test fibre (4). An optical amplifier (8) is provided in the light path between the optical time domain reflectometer (1) and the test fibre (4) for amplifying the light pulses. An optical switch (13) is positioned in the light path between the amplifier (8) and the test fibre (4) for preventing light reaching the test fibre between the light pulses launched by the OTDR (1). Timing means (16, 17) are provided for synchronising the operation of the optical switch (13) so as to open the switch as a light pulse reaches the switch and close the switch as a light pulse leaves the switch.</p> |
