US 11,735,016 B2
Test device for verifying operation of an optical fiber monitoring system utilizing direct optical injection
Cary R. Murphy, Hickory, NC (US); David E. Vokey, Sidney (CA); and Mark K. Bridges, Hickory, NC (US)
Assigned to CYBERSECURE IPS LLC, Bethesda, MD (US)
Filed by Network Integrity Systems, Inc., Hickory, NC (US)
Filed on Oct. 14, 2022, as Appl. No. 17/966,235.
Application 17/966,235 is a continuation of application No. 17/089,186, filed on Nov. 4, 2020, granted, now 11,501,617.
Application 17/089,186 is a continuation in part of application No. 17/018,535, filed on Sep. 11, 2020, granted, now 11,515,940.
Prior Publication US 2023/0069526 A1, Mar. 2, 2023
Int. Cl. H04B 10/071 (2013.01); G08B 13/186 (2006.01); G02B 6/44 (2006.01)
CPC G08B 13/186 (2013.01) [G02B 6/4469 (2013.01); H04B 10/071 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for monitoring an optical fiber for disturbance events caused by physical vibration and/or physical displacement of the optical fiber comprising:
introducing a series of monitoring optical signals into the optical fiber;
receiving optical signals from the optical fiber which are modified by disturbance events on the optical fiber;
in a detection system:
analyzing received signals from the optical fiber after transmission along the optical fiber using OTDR to measure backscattered light to detect the disturbance events to be monitored;
and generating alarms in response to signals which are indicative of the disturbance events to be monitored;
under control of a control system, repeatedly applying to the optical fiber a generated signal which is not caused by an event to be monitored;
the generated signal being applied to the optical fiber by an actuator at a predetermined location on the optical fiber which generates a disturbance event caused by physical vibration and/or physical displacement of the optical fiber;
arranging the generated signal so as to be detected by the detection system when received;
wherein the generated signal contains a recognizable signature for detection by said detection system so as to distinguish at said detection system the generated signal from said disturbance events to be monitored;
in the detection system analyzing the received signals from the optical fiber after transmission along the optical fiber to detect the generated signal;
when the generated signal is detected, reporting detection of the detected generated signal to the control system;
and when said generated signal is not detected, the control system actuating a warning that the detection system is not properly operating.