Non-intrusive optical fibre network

Abstract From the Canadian patent

Abstract of the Disclosure An optical fibre network which does not require the fibre (1) to be broken to introduce new terminals (nodes)(3). Information is introduced into the fibre by modulating, particularly by modulating mode coupling optical power transmitted into the fibre from a source at one or both of its ends. The nodes include tapping means for extracting information. If resonant mode coupling is employed a common grating may be used for introducing and extracting information. Such a non-intrusive network may be overlaid on a conventional local area optical network between two nodes thereof, the fibre being common to both networks. The nodes of the conventional network communicate …