This paper proposes a real-time multi-class disturbance detection algorithm based on YOLO for distributed fiber vibration sensing. The achieves of event location and classification external intrusions sensed by optical sensing system (DOFS) phase-sensitive time-domain reflectometry (Φ-OTDR). We conducted data collection under perimeter security scenarios acquired five types events with total 5787 samples. is used as spatial-temporal image in the training our proposed YOLO-based model (You...

Recently, a type of curved light beams, photonic hooks (PHs), was theoretically predicted and experimentally observed. The production hook (PH) is due to the breaking structural symmetry plane-wave illuminated microparticle. Herein, we presented implemented new approach utilizing symmetry-broken microparticles in material composition for generation PHs from Janus microcylinders. Finite element method-based numerical simulation energy flow-represented theoretical analysis were used...

In this paper, we propose and experimentally demonstrate a scheme of deep learning enhanced long-range fast Brillouin optical time-domain analysis (BOTDA). The volumetric data from BOTDA is denoised demodulated by using video denoising network neural network, respectively. Benefitting the advanced algorithms, sensing range extended to 10 km successfully. experiment, vibration signal measured with sampling rate 23 Hz, 2 m spatial resolution, 1.19 MHz accuracy over single-mode fiber only 4...

Multi-core fiber (MCF) has attracted increasing attention for application in distributed sensing owing to its unique properties of independent light transmission multiple spatial channels. Here, we report a acoustic (DAS) system integrated MCF suppress coherent fading, which overcomes an inevitable challenge DAS systems. Because the parallel cores allow use space-division multiplexed (SDM) technology, propose that fading can be effectively suppressed by merging different signals with...

Recently, two special photonic jets, hooks and twin have been proposed to deal with complex conditions in nanoscale manipulation. Photonic are generated by a single light plane wave an asymmetric microparticle, while the jets produced incident beams. In this letter, we presented demonstrated method combine jets. A symmetric twin-ellipse microcylinder, used research. The curvature degree, length maximum E <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Heterodyne coherent distributed acoustic sensing (DAS) system has witnessed substantial expansion in applications due to its specific advantages like long distance, real-time response and high accuracy. However, the trade-off between vibration bandwidth distance limits broader deployment. The frequency-division-multiplexing (FDM) technique is a well-known solution. But, avoid inter-channel crosstalk, it requires wide (like photodetector modulator) or compromises spatial resolution by...

Heterodyne coherent distributed acoustic sensing (DAS) system has witnessed substantial expansion in applications due to its specific advantages like long distance, real-time response and high accuracy. However, the trade-off between vibration bandwidth distance limits broader deployment. The frequency-division-multiplexing (FDM) technique is a well-known solution. But, avoid inter-channel crosstalk, it requires wide (like photodetector modulator) or compromises spatial resolution by...

We have proposed and demonstrated a weak acoustic signal detection technology based on phase-sensitive optical time-domain reflectometry (Φ-OTDR). Non-contact signals transmitting through air gap between the sound source receiver are difficult to detect due fast attenuation. In order improve ability of non-contact signals, we demonstrate that multi-mode fiber (MMF) is better solution than single-mode (SMF) benefiting from its larger core higher Rayleigh backscattering (RBS) capture...

Distributed acoustic sensing (DAS) is an attractive technology that can turn existing fibre optic networks to real-time distributed vibration sensors. However, it encounters great challenges in handling the transmission, storage, and processing of voluminous data streams which are orders magnitude larger than collected from point The gap between intensive generated by φ-OTDR modern computing system with limited reading/writing speed storage capacity leads restrictions on many applications....

We have proposed and demonstrated the combination of space-division-multiplexing (SDM) frequency-division-multiplexing (FDM) techniques in multicore fiber (MCF) integrated phase-sensitive optical time-domain reflectometry (Φ-OTDR) for achieving fading suppression enhanced signal-to-noise ratio. By using spectral mainlobe sidelobe reconstruction (SMSR) method 2.58-km-long MCF, rate two cores MCF is reduced from 2.21% to 0.02%. And disturbance at 2.55km accurately located restored. The...

The photonic hook, a beam that can propagate along curved path, has attracted wide attention since its inception and experimental confirmation. In this paper, we propose new type of structure, which was made by hollow microcylinder Janus-shaped liquid column two insoluble filling liquids, for producing hook easily tunable properties long length. E^2 field intensity distribution characteristics formation mechanism the are studied analyzing energy flow using finite element method. profile be...

Photonic nanojet (PNJ) is a tightly focused, non-resonant and spatially highly confined light beam that emerging on the shadow side surface of light-illuminated lossless dielectric microparticle with diameter comparable or slightly larger than wavelength incident light. PNJ's significant properties subwavelength transverse beamwidth, high intensity propagation capability extending evanescent field region make it get lot applications in broad range areas, such as optical signals enhancement,...

In recent years, deep convolutional neural networks (CNNs) have been widely used for hyperspectral image (HSI) classification. Besides, ensemble learning is a useful way to enhance the classification performance. Therefore, in this study, new method titled Boosting-CNN proposed HSI classification, which fully explored advantages of CNN and learning. Specifically, several CNNs are well-designed classify HSI. The samples misclassified more weighs following through adaptive boosting. final...

Phase-sensitive optical-time domain reflectometry (Φ-OTDR) is able to detect vibrations effectively with high sensitivity. It achieves by interrogating coherent Rayleigh backscattering (RBS) light in sensing fiber. However, fiber undergoes fading caused phase extinction interference or polarization mismatching. Fading will result serious false alarms when locating real vibration events, especially weak signal detection. In order suppress and exclude improve localization accuracy, we propose...

The upper frequency of vibration detected by the conventional phase-sensitive optical time-domain reflectometer (Φ-OTDR) is limited detection fiber length. In order to achieve long-range sensing and high-frequency partial discharge detection, we propose a scheme hybrid Φ-OTDR Mach-Zehnder interferometer (MZI) based on multicore fiber. One cores performs function Φ-OTDR, two other perform arms MZI. As proof concept, simulation results demonstrate successful demodulation high vibration, which...

Recently, two special photonic jets, hooks and twin have been proposed to deal with complex conditions in nanoscale manipulation. Photonic are generated by a single light plane wave an asymmetric microparticle, while the jets produced incident beams. In this letter, we presented demonstrate method combine jets. A symmetric twin-ellipse microcylinder, used research. The curvature degree, length maximum E2 filed enhancement of varied significantly, change refractive indices shape...

Distributed acoustic sensing (DAS) is a novel enabling technology that can turn existing fibre optic networks to distributed sensors. However, it faces the challenges of transmitting, storing, and processing massive streams data which are orders magnitude larger than collected from point The gap between intensive generated by DAS modern computing system with limited reading/writing speed storage capacity imposes restrictions on many applications. Compressive (CS) revolutionary signal...

One of the challenges in distributed acoustic sensing (DAS) system is how to transmit, store, and process massive streams data. In this work, we propose a novel classification method compressed-domain for DAS Our compresses signal reduce data size classify different vibration events using compressed directly. We experimentally verified that 90% accuracy can be achieved on four-class task with only 30% original size. Classification under SNRs measurement ratios are also investigated work.

Signal to noise ratio (SNR) plays a considerably important role in distributed acoustic sensing (DAS) applications. Gradually, single mode fiber (SMF) shows limitations gradually SNR improvements. In this article, we propose enhancement phase-sensitive optical time domain reflectometry (Φ-OTDR) system for DAS. The main element is that multimode (MMF) has been used as the under test (FUT) instead of SMF. We demonstrate advantages MMF by comparing above two links launched into Φ-OTDR various...