Abstract: An advance in the art is made according to aspects of the present disclosure directed to the detection and localization of a substantially static weight situated on aerial telecommunications fiber optic cable through the effect of phase-distributed acoustic sensing (?-DAS) and signal analysis of ambient data. In sharp contrast to the prior art, our inventive method does not require a special optical fiber arrangement or type of fiber nor is it susceptible to range limitations that plague the prior art.

Abstract: Aspects of the present disclosure describe the localization of a utility pole by distributed fiber sensing of aerial fiber cable suspended from the utility pole.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously enable city-scale acoustic impulse detection and localization using standard, live aerial telecommunications optical fiber cables through the use of distributed acoustic sensing exhibiting an error of less than 1.22 m.

Abstract: An advance in the art is made according to aspects of the present disclosure directed to distributed fiber optic sensing systems (DFOS), methods, and structures that advantageously provide the continuous monitoring of aerial cables using distributed acoustic sensing (DAS) and operational modal analysis (OMA).

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously enable and/or facilitate the continuous, real-time monitoring and identification vehicle speed, vehicle direction, vehicle axle width, vehicle type, total number of vehicle axles, and vehicle count. The DFOS sensing fiber is advantageously positioned underneath a roadway/highway in a novel arrangement/layout and temporal measurements are made to provide vehicle identification.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously enable and/or facilitate the continuous monitoring and identification of damaged utility poles by employing a DFOS distributed acoustic sensing (DAS) methodology in conjunction with a finite element analysis and operational modal analysis. Of particular advantage and in further contrast to the prior art, systems, methods, and structures according to aspects of the present disclosure utilize existing optical fiber supported/suspended by the utility poles as a sensing medium for the DFOS/DAS operation.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS)—distributed acoustic sensing (DAS) based systems, methods, and structures that advantageously enable and/or facilitate the determination of natural frequency(ies) of civil infrastructures.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS)-distributed acoustic sensing (DAS) based systems, methods, and structures that advantageously enable and/or facilitate the monitoring of civil infrastructures via acoustic wave speed measurements.

Abstract: Systems and methods for implementing and using optoelectronic gates are disclosed. One such method includes superimposing an electrical data bit onto a first optical input to produce a pair of first-stage optical outputs. The first one of the pair of first-stage optical outputs carries the electrical data bit and the second carries the complement of the electrical data bit. The method further includes comparing an electrical target bit with the electrical data bit conveyed by the first first-stage optical outputs and with the complement of the electrical data bit conveyed by the second first-stage optical outputs, to determine whether the electrical target bit and the electrical data bit are same or different.

Abstract: Systems and methods for implementing and using optoelectronic gates are disclosed. One such method includes superimposing an electrical data bit onto a first optical input to produce a pair of first-stage optical outputs. The first one of the pair of first-stage optical outputs carries the electrical data bit and the second carries the complement of the electrical data bit. The method further includes comparing an electrical target bit with the electrical data bit conveyed by the first first-stage optical outputs and with the complement of the electrical data bit conveyed by the second first-stage optical outputs, to determine whether the electrical target bit and the electrical data bit are same or different.

Abstract: Methods, systems, apparatus and devices for using a modified PDH technique to measure the FSR of an etalon with one part per 104 precision.

Abstract: Methods and devices for a coupled optoelectronic oscillator having optical frequency stabilization. The coupled optoelectronic oscillator includes a harmonically mode-locked laser cavity having a Mach-Zehnder modulator for mode-locking and an intracavity Fabry-Perot etalon to allow only one single supermode to lase, a stabilization loop coupled with the Fabry-Perot etalon to detect changes in the laser cavity optical frequency and generate an error signal to compensate for the frequency change to stabilize the mode-locking of the laser frequency stabilization, and an electrical loop between the laser cavity and the stabilization loop for driving the Mach-Zehnder modulator with the coupled optoelectronic oscillator signal.