| 摘要 |
<p>An electronic telephone exchange of the type employing time-space-time switching, has an optical fibre data link connecting the space and time switches. In order to meet the design requirements for use in a telephone exchange, the fibre optic link has to have fairly well defined performance parameters. In particular the overall diameter of the optical fibres employed in the optical fibre link lies between 180 and 250 microns, preferably 200 microns, and the core diameter of the optical fibres lies in the range 0.6 to 0.95 of the cladding diameter. Preferably the core diameter lies in the range 160-180 microns. The optical fibre link is characterised by the numerical aperture of the fibre, insertion loss of the fibres sensitivity and dynamic range of detector, and the power output and extinction ratio of the transmitter.</p> |
