Systems, methods, and structures for colorless distributed fiber optic sensing/distributed vibration sensing (DOFS/DVS) over dense wavelength division multiplexing (DWDM) telecommunications facilities that operate over a C-band wavelength range spanning from 1525 nm to 1565 nm wherein the DOFS/DVS systems exhibit suitable reconfigurability of its wavelength to match a wavelength of a desired testing channel and may advantageously provide DOFS/DVS capabilities to existing DWDM communications infrastructure as a retrofit. Colorless DFOS/DVS systems according to the present disclosure include a length of optical sensor fiber; a colorless DFOS/DVS interrogator in optical communication with the optical sensor fiber, said colorless DFOS/DVS interrogator configured to generate optical pulses, introduce the generated pulses into the length of optical sensor fiber, and receive backscattered signals from the length of the optical sensor fiber; and an intelligent analyzer configured to analyze colorless DFOS/DVS data received by the DFOS/DVS interrogator and determine from the backscattered signals, vibrational activity occurring at locations along the length of the optical sensor fiber.

A method for underground cable localization by fast time series template matching and distributed fiber optic sensing (DFOS) includes: providing the DFOS system including a length of optical sensor fiber; a DFOS interrogator in optical communication with the optical sensor fiber, said DFOS interrogator configured to generate optical pulses, introduce the generated pulses into the length of optical sensor fiber, and receive backscattered signals from the length of the optical sensor fiber; and an intelligent analyzer configured to analyze DFOS data received by the DFOS interrogator and determine from the backscattered signals, vibrational activity occurring at locations along the length of the optical sensor fiber; deploying a programmable vibration generator to a field location proximate to the length of optical sensor fiber; transmitting to the programmable vibration generator a unique vibration pattern to be generated by the vibration generator; and operating the programmable vibration generator to generate the unique vibration pattern transmitted; and operating the DFOS system and collecting/analyzing the determined vibrational activity to further determine vibrational activity indicative of the unique vibration pattern generated by the vibration generator.

Aspects of the present disclosure describe systems, methods and structures providing detection and localization of disaster-related indoor events via hybrid ethernet/optical fiber cable.

Disclosed are distributed fiber optic sensing arrangements that—in sharp contrast to the prior art—utilize C-OTDR capabilities to detect an optical fiber end point while still maintaining operational DFOS vibration/acoustic signal sensing functions. Advantageously, such operations are performed automatically without requiring a manual confirmation. A change is made in digital signal processing in the C-OTDR operation by bypassing a high-pass-filtering stage when calculating intensity changes such that the DC signal component is preserved and used to differentiate from a “no-fiber” section. It then calculates the no-fiber section's signal level and uses a back-tracking operation to determine the fiber end automatically.

Systems, methods, and structures for efficiently identifying individual fibers located in a deployed cable that advantageously reduces laborious field efforts while reducing service outage time. The systems and methods locate a targeted fiber in a cable (“Cable ID”) and then identify the targeted fiber (“Fiber ID”) by detecting DFOS signal attentions—without cutting the optical fiber. Two distinct determinations may be made namely, Cable ID and Fiber ID. DFOS operation detects vibration signals occurring along a sensor fiber. As implemented, Cable ID is an interactive-machine learning-based algorithm that automatically locates cable position along a sensor fiber route. Fiber ID detects a signal attenuation by bending a group of fibers with bifurcation to pinpoint a targeted individual fiber within a fiber cable.

A fiber optic sensor interrogation system with inbuilt passive power limiting capability based on stimulated Brillouin scattering that provides improved safety performance for use in explosive atmospheres.

Air property measurement (e.g., air temperature, air density, etc.) sensors may take the form of an all-fiber-optic device employing Rotational Raman light detection and ranging technology. Not only do the fiber optic devices described herein require no moving parts, but also these devices may be compact in design and require less power to operate as compared to conventional apparatus. As a result, embodiments may be used in applications in which physical space and power demands may be limited, such as in aircraft.

A system comprises a housing, a light source, a light guide configured to guide a light from the light source. The light guide includes a plurality of detection target configured to provide optical effect on the light in accordance with a bend state of the light guide. A light detector is configured to detect the light emitted from the light guide and provide information of the detected light. A communication unit is configured to transmit wirelessly the information of the detected light. The communication unit is disposed in the housing.

Brillouin optical distributed sensing device and method is provided and includes a structure for generating an optical pulsed signal and an optical probe signal. The structure includes a circulation component for directing the optical pulsed signal to a sensing optical fiber, and directing an optical measurement signal with Brillouin scattering information arising from the sensing optical fiber toward a detection apparatus. Also included is an optical routing component for configuring the device to allow generating: (i) according to a first configuration, an optical measurement signal with stimulated Brillouin scattering information resulting from the interaction of the optical pulsed signal, and an optical probe signal propagating in the sensing optical fiber in a direction opposite to the optical pulsed signal, or (ii) according to a second configuration, an optical measurement signal with spontaneous Brillouin scattering information resulting from the propagation of the optical pulsed signal in the sensing optical fiber.

System and method of distributed sensing based on Brillouin stimulated scattering on optical fiber (3), consisting of separating the two signals of which the probe signal is composed and obtaining the difference between the stimulated amplification band (8) and the attenuation band (9), or vice-versa. In this way a signal is obtained with greater amplitude than in the case of detection being performed with a single band. Thus the signal-to-noise ratio is improved in the sensor signal, dynamic range and the range is increased and the uncertainty of the measurement is decreased. It also eliminates the common noise present in the two bands of the probe signal and, in the case of using a balanced detector in detection, it improves the saturation characteristics of the detector, being able to achieve much larger signal amplitudes than in the conventional case.