<title>Time-division-multiplexed matrix-addressed FOS network of three dimensions</title>

Abstract

A group of sensors in a ladder OFS network, in general, employs two main optical fibers, the feed fiber and the return fiber. As another feed fiber, called nth feed fiber, is introduced into the ladder network, another group of sensors which uses the original return fiber path and the nth feed fiber as its feed path can be identified with address code n. On the other hand, as another return fiber, called mth return fiber, is introduced into the ladder network, a new sensor group which uses original feed fiber path and the mth return fiber as its return path also can be identified with the address code m. When both the nth feed fiber and the mth return fiber are introduced into a ladder network, a 3-dimensional OFS network is formed. In a basic ladder OFS network, the individual sensor is identified by a time coded system with the detected kth pulse. Therefore, the 3-dimensional network can be identified by 3 integer variables (k, m, n). When k, m, n take the values from 1 to N, it can be achieved in a 3- dimensional OFS network that the N X N X N sensors are monitored by means of 2 X N optical fibers. A temperature sensor system using the 3-D network is being implemented in our lab.