We propose a novel technique for chaotic correlation optical time domain reflectometer with millimeter and range- independent spatial resolution. Utilizing waveforms generated from laser diode an fiber ring feedback, proof-of-concept experiment is demonstrated 6-cm resolution in the 0 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">~</i> 140 m range, which limited by bandwidth of real-time oscilloscope used.

We demonstrate experimentally and numerically a method using the incoherent delayed self-interference (DSI) of chaotic light from semiconductor laser with optical feedback to generate wideband signal. The results show that, DSI can eliminate domination relaxation oscillation existing in therefore flatten widen power spectrum. Furthermore, depresses time-delay signature induced by external cavity modes improves symmetry probability distribution more than one magnitude. also that this signal...

We propose a method to locate precisely faults in wavelength-division-multiplexing (WDM) passive optical network (PON) by using wavelength tunable chaotic laser. The laser consists of multiple-longitudinal-mode Fabry-Perot (FP) diode whose modes match the channels WDM-PON, and an feedback loop including filter. feeds proportion light one mode that passes through filter back into cavity generate light. By adjusting frequency, we can tune light, diagnose corresponding branch WDM-PON....

Electroslag remelting (ESR) experiments were performed on 304L austenitic stainless steel using a laboratory-scale low-frequency electroslag furnace with Al 2 O 3 -CaO-CaF and -CeO -CaF slags of varying compositions. The study aimed to evaluate the influence slag composition oxygen nitrogen content, as well number, size, types inclusions in ESR ingots under power supply conditions. results demonstrated that, conditions, increasing CaO or CeO content while decreasing significantly reduced...

Abstract Micro/nanoscale lasers that span the entire visible spectrum, especially those in red, green, and blue colors, are not only essential for a variety of optical devices but also have important applications color communication, multi‐color fluorescence sensing, wavelength division multiplexing. Despite great efforts made to achieve lasing using approaches, on‐chip white light emission even still suffer from considerable challenges micro‐nano structures. Here, CdS x Se 1−x , CdS, ZnS...

Ground-penetrating radar (GPR) is an effective tool for underground object detection, but its data interpretation remains a great challenge. In this letter, we propose novel classification algorithm using deep 3-D convolutional networks (C3D) and multiple mirror encoding (MME) GPR data. Although learning technique has been applied to interpret the data, most of existing methods are based on B-scans have relatively low accuracy since reflections from various subsurface targets present similar...

A chaotic radar system has been developed for through-wall detection and ranging of targets. The signal generated by an improved Colpitts oscillator is designed as a probe signal. Ranging to target achieved the cross-correlation between time-delayed reflected return replica transmitted In this paper, we explore performance through lossy media. Experimental results show that advantages high range resolution, unambiguous correlation profile, can be used wall sensing.

We experimentally demonstrate radar remote imaging using a radio technique based on ultra-wideband chaotic signals over fiber links. The system includes three parts, i.e. central station, some optical links and base station. At the an signal is generated from improved Colpitts oscillator then up-converted as probe signal. converted to be in domain by external modulation laser diode for transmitting link electrical launched microwave antenna. After being received another antenna, echo target...

The time-delay signature and the chaos bandwidth in three-cascaded vertical-cavity surface-emitting lasers have been investigated experimentally. A peak value of autocorrelation coefficient at feedback round trip time ratio between this its background are used to quantitatively identify (TD) chaos. new concept-peak side-peak is introduced for better quantification TD concealment. defined as a delay other than zero time. Three injection cases, namely, small bandwidth, intermediate wide...

The time delay signature is a crucial secure key for chaos communication using optical feedback semiconductor lasers. Herein, we propose single node-based photonic reservoir computing method extracting the of optical-feedback-induced chaos. Through drawing phase diagram chaotic series and its delayed copies, transform into shape feature obtained two-dimensional image. After training optimized with these images, numerically demonstrate that our can achieve an overall extraction accuracy rate...

Chaos optical time-domain reflectometry (chaos OTDR) has an advantage of high spatial resolution without tradeoff measure distance by utilizing correlation detection based on broadband chaotic laser. However, achieving a usually requires wideband photodetector and high-speed data acquisition card. In this letter, we propose significant-bit method to improve the chaos OTDR instead increasing hardware bandwidth. method, reference echo signals are quantized with multi-bit analog-to-digital...

Chaos through-wall imaging radar has attracted wide attention due to its inherent low probability of detection/interception, strong anti-jamming, and high resolution. However, the target response is usually overwhelmed by clutter. This paper proposes an imaging-then-decomposition method based on two-stage robust principal component analysis (RPCA) remove clutter recover image. The proposed firstly focuses energy preprocessing data back-projection algorithm; then, it performs matrix...

An experimental wideband chaotic ground penetrating radar is proposed to locate underground pipes. A signal with a bandwidth of 1.56 GHz utilized as the probe signal. The localization pipes achieved by correlating echo its delayed duplicate and back-projection algorithm. Experimental results demonstrate that plastic pipe, metallic multiple can be located range resolution 10 cm. Limited height sand, detectable estimated 0.7 m for both when transmitting power −12 dBm. system has potential...

A correlation weighted back projection (CWBP) imaging algorithm is proposed to suppress artifacts introduced by the classic (BP) in application of chaotic ground-penetrating radar (GPR). In CWBP algorithm, backscattering response each point region first reconstructed through weighting, which used highlight targets. Then quadratic cross calculated reduce nontargets' backscattering. The experimental results show that are significantly suppressed. addition, ghosts generated overlapped...

摘要: 针对渤海湾盆地辽中凹陷南洼古近系地层超压成因问题,通过对多种地质资料和研究方法综合应用,提出生烃作用是超压形成的主要机制,在局部地区(W-D构造)存在欠压实和生烃作用叠加形成的超压.主要证据如下:(1)测井曲线除W-D构造外,普遍不具备欠压实地层高孔隙度和低密度的典型特征;(2)沉积背景分析由欠压实作用形成超压的顶面深度与实际不符;(3)超压顶面发育在大套泥岩段内部,深度变化范围较大(2 200~3 100 m),与烃源岩生烃顶面基本一致;(4)地层有效应力和速度及密度关系表明,超压点均落在"卸载"曲线上,为生烃超压的特征;(5)超压段地层现今处于大量生烃阶段,持续为超压形成提供保证;(6)欠压实作用和生烃作用叠加形成的超压,导致了地层的高孔隙度和低密度,也使地层有效应力与地层速度和密度关系曲线表现出"卸载"现象. 关键词: 沉积 / 生烃作用 欠压实作用 超压成因 辽中凹陷南洼 渤海湾盆地 石油地质

A high-resolution leaky coaxial cable (LCX) sensor for perimeter intrusion detection is proposed and experimentally demonstrated. In our system, a wideband Boolean-chaos signal used as the probe signal, pair of cables (LCXs) applied transmitting receiving echo respectively. By correlating chaotic with its delayed duplicate comparing correlation traces before after intrusion, intruder can be accurately located. Experimental results demonstrate simultaneously detect multiple intruders. The...

Clutter removal is of vital importance to underground detection via ground penetrating radar (GPR) since the target response usually overwhelmed by strong clutter. The low-rank and sparse decomposition (LRSD) method, which decomposes GPR data into a background matrix matrix, has been applied in GPR. However, existing LRSD-based methods, such as robust principal component analysis (RPCA) non-negative factorization, are sensitive regularization parameter or have high computation complexity. In...

We present numerically an all-optical approach to generate fast physical random numbers. This is based on chaotic self-pulsations, a kind of chaos superimposed periodic pulse trains. Two-section semiconductor lasers (TSSLs) can exhibit this phenomenon chaos, under appropriate external optical injection. Simulations demonstrate that, without sampling and postprocessing procedures, technique produce numbers at gigabit per second rates through directly quantizing the self-pulsations via...

Chaotic laser radar based on correlation detection is a high-resolution measurement tool for remotely monitoring targets or objects.However, its effective range often limited by the side-lobe noise of trace, which always increased randomness chaotic signal itself and other transmission channel noises interferences.The experimental result indicates that wavelet denoising method can recover real lidar in strong period disturbance, signal-to-noise ratio about 8 dB increased.Moreover, average...

A hybrid life detection radar system which transmits a wideband chaotic signal containing an embedded single-tone is proposed. The used for target localization by the time-domain correlation method and synthetic aperture technique, to measure frequencies of breathing heartbeat based on on-chip split-ring integrated sensor Michelson interference principle. Experimental results in free space through-wall scenarios demonstrate that can realize human simultaneously with high range resolution,...

A polarimetric chaotic ground penetrating radar (GPR) is proposed to improve the detection accuracy of underground pipes. In this system, signal used as probe and multi-polarization mode employed gather GPR data. Furthermore, laplacian pyramid algorithm applied fuse components. The simulations demonstrate that by using polarization GPR, pipe responses are enhanced their shape distribution can be accurately obtained. Here, information entropy, average gradient, spatial frequency, standard...

A Golay-based ultra wideband ground penetrating for underground pipes location is proposed and experimentally demonstrated. Golay complementary codes with the code length of 1024 frequency 1 GHz are used as probe signals. The two-dimensional image buried achieved by a correlation method back-projection algorithm. experimental results show that both plastic pipe metallic can be located range resolution 10 cm. Furthermore, sequences pair sequences, sum their function yields twice value peak at...

We generate a macro-pulsed chaotic laser based on pulse-modulated diode subject to free space optical feedback, and demonstrate the performance of suppressing backscattering interference jamming in turbid water. The with wavelength 520 nm as transmitter is used correlation-based lidar receiver perform an underwater ranging. At same power consumption, lasers have higher peak than continuous-wave form, enabling former detect longer experimental results show that has excellent water column...

Phenols are common pollutants in many industrial wastewaters, posing tremendous harm to ecosystem. In this work, ternary extractant, containing tributyl phosphate/n-octanol/cyclohexane, was utilized achieve the purpose of liquid–liquid extraction from phenol-bearing aqueous samples. Besides, respond surface methodology employed evaluate and further optimize proportion components. FT-IR spectroscopy results have demonstrated that hydrogen bonding between phosphate phenol make a great...