| 摘要 |
<p>COHERENT REFLECTOMETER An optical reflectometer in which the output from a laser 11 is passed through a ramped phase modulator 12 and an optical fibre bi-directional coupler 13 to a transmission path 15, e.g. an optical fibre. Part of the light is coupled out to a mirror 14 and is reflected to form a local oscillator signal which is mixed in the coupler with backscattered light from the fibre. The mixed signals are applied to a detector 16.</p> |
