摘要 |
<p>An optical time domain reflectometry apparatus for sensing a parameter to be measured in a region of interest comprises an optical fibres, source means 1 operable to launch optical radiation into the optical fibre at a probe wavelength; and detection means 2 operable to produce electrical output signals in response to optical radiation backscattered from the optical fibre; and wherein the optical fibre comprises a first section 50 , into which optical radiation at the the probe wavelength having a preselected intensity is launched, and a second section 60 deployed in the region of interest, there being a remote amplifier arranged between the first and second sections which is operable to compensate for attenuation losses in the intensity of the probe wavelength in the first section.</p> |