ADP switch and adjustable data acquisition window
First Claim
1. An OTDR comprising a light source to transmit an optical pulse to and along an optical fibre to be tested, an optical receiver to detect an optical signal produced by reflection of said pulse as it passes along said fibre and to produce an electrical signal corresponding thereto, an amplifier having an input to receive said electrical signal and an output to direct said signal to a signal processor to obtain an indication of the variation of said signal as said pulse passes along said fibre, an input switch to regulate the passage of said signal from said receiver to said input and having a first condition in which said receiver is disconnected from said amplifier and a second condition in which said receiver is connected to said amplifier, monitoring means to monitor said received signal and identify periods during which said electrical signal exceeds a predetermined value, selection means to select one of said periods and control means to maintain said switch in said first condition prior to said selected one of said periods and in said second condition thereafter.
3 Assignments
0 Petitions
Accused Products
Abstract
An OTDR to examine light reflected from an optic fibre has an amplification stage that operates in either a high gain or low gain mode. To avoid saturation of the amplifier in the high gain mode, the trace is examined to identify the location of spikes and a switch is controlled to connect the amplifier to the signal after the occurrence of the spike.
36 Citations
11 Claims
- 1. An OTDR comprising a light source to transmit an optical pulse to and along an optical fibre to be tested, an optical receiver to detect an optical signal produced by reflection of said pulse as it passes along said fibre and to produce an electrical signal corresponding thereto, an amplifier having an input to receive said electrical signal and an output to direct said signal to a signal processor to obtain an indication of the variation of said signal as said pulse passes along said fibre, an input switch to regulate the passage of said signal from said receiver to said input and having a first condition in which said receiver is disconnected from said amplifier and a second condition in which said receiver is connected to said amplifier, monitoring means to monitor said received signal and identify periods during which said electrical signal exceeds a predetermined value, selection means to select one of said periods and control means to maintain said switch in said first condition prior to said selected one of said periods and in said second condition thereafter.
Specification