Journal of Lightwave Technology最新文献

{"title":"Dual Stimulated Brillouin Scattering Based Wideband Instantaneous Frequency Measurement","authors":"Jingbo Li;Wei Zhao;Jianping Chen;Guiling Wu","doi":"10.1109/JLT.2026.3707146","DOIUrl":"https://doi.org/10.1109/JLT.2026.3707146","url":null,"abstract":"A wideband instantaneous frequency measurement (IFM) scheme based on dual stimulated Brillouin scattering (Dual-SBS) is proposed to achieve bandwidth extension. A signal under test (SUT) is carrier-suppressed double-sideband modulated, and the generated double-sideband optical signal is amplified to serve as the pump light for exciting the Dual-SBS process. A linear frequency modulation (LFM) signal is second-order modulated to realize an enlarged frequency-sweeping range and serve as the probe light. The interaction between the pump and probe light excites the Dual-SBS effect, producing either one or two pulses depending on the SUT frequency. An unambiguous and bandwidth-extended frequency-to-time mapping relationship is established based on the number of pulses and the temporal position of the rightmost pulse. A waveform-customized LFM signal with a starting flag is further designed to provide a temporal reference for time measurement, eliminating the need for an additional reference signal. In addition, a real-time online Brillouin frequency shift estimation method is provided by measuring the temporal spacing between pulses, without interrupting the link. A proof-of-concept experiment is demonstrated. By employing a 5.4–35 GHz waveform-customized signal consisting of a 1.2 <inline-formula><tex-math>$mu$</tex-math></inline-formula>s starting-flag segment and an 88.8 <inline-formula><tex-math>$mu$</tex-math></inline-formula>s LFM segment, an IFM with a directly validated measurement range of 0–40 GHz and an equivalent measurement over 40–80 GHz is achieved, featuring errors below 1.5 MHz, an interception period of 90 <inline-formula><tex-math>$mu$</tex-math></inline-formula>s, and a multi-tone frequency resolution of approximately 30 MHz.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7412-7420"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-Scale Strain Sensing of OFDR via 2-D Pattern-Matching Method in Spatial-Spectral Domain","authors":"Xinyue Yu;Xing Liu;Jingqi He;Shuaiqi Liu;Yaxi Yan;Dexin Ba;Yongkang Dong","doi":"10.1109/JLT.2026.3713496","DOIUrl":"https://doi.org/10.1109/JLT.2026.3713496","url":null,"abstract":"Large-scale strain induces the spatial deviation within fiber and spectral shift of Rayleigh scattering spectrum (RBS), resulting in a joint spatial-spectral mismatch that decreases the correlation of the RBS pattern in the optical frequency-domain reflectometry (OFDR) systems. In this letter, we propose a novel demodulation scheme based on two-dimensional (2-D) pattern-matching method, qualifying the coherence between the reference and measurement signals in the spectral–spatial domain. The proposed method treats the RBS as a 2-D image, where a localized reference RBS pattern serves as a template, and full-size measured RBS serves as the target. Through the convolution of the template pattern over the target pattern, the optimal wavelength shift and position offset are simultaneously determined for distributed large-strain sensing. Experimental results demonstrate the distributed strain sensing up to 10000 μϵ over a 1 m segment at the end of 22 m-long sensing fiber, with the spatial resolution of 3.1 mm. The proposed 2-D demodulation framework effectively compensates for accumulated spatial deviation and accurately resolves strain-induced wavelength shift, offering a new demodulation strategy for high-fidelity distributed sensing with improved robustness and accuracy in large-scale strain measurement systems.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7729-7734"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fiber-Optic Chromatic Dispersion Measurement Based on Enhanced Precision Group Delay Synthesis","authors":"Jun Guo;Bing Wei;Hanfeng Xu;Wenhao Zhang;Chen Xu;Xiaofeng Jin","doi":"10.1109/JLT.2026.3709983","DOIUrl":"https://doi.org/10.1109/JLT.2026.3709983","url":null,"abstract":"Fiber-optic chromatic dispersion (CD) measurement based on enhanced precision group delay synthesis is proposed and demonstrated. A differential phase approach under optical single-sideband (OSSB) modulation at specific radio frequencies is employed to achieve accurate optical time delay measurement by eliminating the nonlinear interference of group velocity dispersion. By scanning only a few radio-frequency tones, high-precision CD values can be retrieved from the measured non-true time delay, circumventing continuous optical wavelength sweeping. Measurement deviation caused by non-ideal OSSB modulation is theoretically investigated and a correction model is proposed for the compensation of non-ideal modulation. Experimental characterization of two dispersion compensation modules (DCMs) yields CD values of −163.648 ps/nm at 1552.89 nm with deviation of 2.542 ps/nm for dispersion compensation of 10 km standard single-mode fiber (SMF), and −330.076 ps/nm at 1545.0 nm with deviation of 1.635 ps/nm for 20 km SMF compensation module. For a chirped fiber Bragg grating (CFBG), the CD is measured to be −747.144 ps/nm at 1553.0 nm with deviation of −17.118 ps/nm. The proposed method features high CD accuracy, simple operation, as well as the ability to extract both group delay and dispersion by scanning only a few radio-frequency tones.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7535-7542"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-Low Noise Figure of Erbium-Doped Fiber Amplifier Enabled by Nested Anti-Resonant Hollow-Core Fiber","authors":"Zirui Chen;Jianxiang Wen;Yanhua Luo;Fufei Pang;Hairul Abdul Rashid;Gang-ding Peng;Tingyun Wang","doi":"10.1109/JLT.2026.3711360","DOIUrl":"https://doi.org/10.1109/JLT.2026.3711360","url":null,"abstract":"Driven by the demand for high-capacity communication systems, a novel erbium-doped fiber amplifier with an ultra-low noise figure, based on a nested anti-resonant hollow-core fiber (NC-ARHCF) is investigated. A theoretical model for light-matter interaction within the doped regions of the cladding tubes is established, employing the normalized power density distribution (NPDD) instead of the conventional overlap factor to calculate fiber gain. When the wall thickness and refractive index of the doped cladding tube are set to 0.9765 μm and 1.5, respectively, and the active particle doped in the outer-ring doping regions, and further a higher-order pump light mode, the fiber achieves a maximum gain exceeding 37 dB. The gain bandwidth exceeds 50 nm with a gain above 27 dB and improved flatness. Owing to the absence of light-matter interactions in the hollow-core transmission region, the noise figure is reduced to as low as 2.95 dB, while the minimum confinement loss is also up to 0.15 dB/km. These findings provide a new route for next-generation ultra-low noise, high-gain fiber amplifiers and offer valuable insights for future ultra-low latency and ultra-high capacity communication systems.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7684-7694"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flat Electro-Optic Frequency Comb Generation Based on a Single-Drive Asymmetric Modulator","authors":"Yuzhe Sun;Hao Yao;Jiayao Deng;Hao Zhang;Xiaoxia Ma;Mengke Wang;Jieyun Wu;Kaixin Chen","doi":"10.1109/JLT.2026.3706978","DOIUrl":"https://doi.org/10.1109/JLT.2026.3706978","url":null,"abstract":"Recent advances in high-performance electro-optic (EO) modulators based on the lithium niobate on insulator (LNOI) platform have significantly accelerated the development of on-chip EO frequency combs. For practical applications of the combs, high spectral flatness is crucial. Conventional methods, such as using dual-drive or cascaded modulators, can generate numerous spectrally flat comb lines. However, both approaches necessitate multiple off-chip microwave driving components, increasing the complexity of the chip architecture and overall system, as well as complicating system control. Here, we demonstrate first, to the best of our knowledge, the generation of flat on-chip EO frequency comb using an asymmetric LNOI modulator driven by a single microwave signal. Our fabricated asymmetric modulator successfully generates 11 comb lines with a spectral flatness within 6.11 dB at a repetition rate of 18 GHz. The operation wavelength can be tuned over a 160-nm range from 1480 to 1640 nm, while the repetition rate can be tuned continuously from 18 to 25 GHz. Our proposed device offers the advantages of a simple on-chip layout and driving circuits, which simplifies fabrication and enables high-performance, low-power, and cost-effective EO comb.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7500-7507"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longitudinal Power Profile Estimation in Optical Networks Using Reconstruction-Based Super-Resolution MMSE","authors":"Zhudong Shi;Guanlin Liu;Xulong Yan;Xu Yang;Xian Zhou","doi":"10.1109/JLT.2026.3706098","DOIUrl":"https://doi.org/10.1109/JLT.2026.3706098","url":null,"abstract":"This paper proposes an improved minimum mean square error (MMSE) based algorithm, called reconstruction-based super-resolution MMSE (SR-MMSE), for fiber-longitudinal power profile estimation (PPE). This study introduces a reconstruction-based super-resolution (SR) technology into PPE. By shifting the initial sampling position, multiple sets of sub-spatial-granularity shifted MMSE estimates can be extracted. Subsequently, by leveraging the mapping relationship across different spatial granularities, a power profile with a finer spatial granularity is reconstructed. We mathematically analyze the feasibility of this technology and quantify the model errors. Simulation results demonstrate that the SR-MMSE method can derive a power profile with a finer spatial granularity, exhibiting the potential to optimize localization performance in anomalous attenuation scenarios and achieve a finer spatial resolution, providing a novel optimization approach for PPE.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7594-7605"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of All-Optical and Electro-Optic Phase Encoding Quantum Key Distribution at O-Band","authors":"Cheng-Lin Tsou;Gong-Ru Lin","doi":"10.1109/JLT.2026.3707333","DOIUrl":"https://doi.org/10.1109/JLT.2026.3707333","url":null,"abstract":"O-band carrier has long been ignored for optical quantum key distribution (QKD) application owing to the broader laser linewidth, larger fiber loss, and lower wavelength tolerance, despite the only advantage of its dispersion-free transmission in standard single-mode fiber (SSMF). Nonetheless, the secure data transmission at O-band is still an intriguing target as most of the short-reach SMF-based metropolitan or data-center networks demand the optical cryptography solutions. By comparing four types of all-optical or electro-optic differential-phase-shift (DPS) encoding techniques, this study details the key-rate/error/distance performances by using a pulsated carrier generated from a TO-can packed distributed feedback laser diode (DFBLD). At a carrier wavelength of 1308.4 nm with a limited encoding bandwidth of 1.5 GHz, the comparison on temporal stability, coding efficiency, and cost effectiveness is performed for four DFBLD-based DPS-QKD systems using external or direct modulation schemes for the QKD-bit generation. The adiabatic-controlled master and slave (M and S) DFBLD carrier maintains its stability with ΔP/P variation below 0.1% at an average power of 0.68 mW for 30 minutes. After passing through the delay interferometer with -3.2-dB loss, the wavelength-induced transient power fluctuation significantly reduces to 0.006 mW/s with ΔP/P of 1.89%. The DPS-QKD using a cost-ineffective DFBLD+EOM-IM/PM (M→IM→PM) scheme is treated as a DPS-QKD reference, degrading its QBER from 2.3% to 3.7% with allowable SKR decreasing from 50 to 0.18 kbit/s in a 15-km SSMF link. Using the M-to-S OIL-DFBLDs with external PM (M→PM→S) can provide a QBER of 2.94% and an SKR of 27 kbit/s under back-to-back transmission, which degrades to QBER = 3.45% and SKR = 4.37 kbit/s after 12-km SSMF. The M-to-S OIL-DFBLDs with external IM (M→IM→S) degrade QBER and SKR from 3.03% and 24 kbit/s (at back-to-back link) to 3.45% and 5.34 kbit/s over 9-km SSMF. In contrast, the low-cost compact M-to-S OIL-DFBLDs with DM-PM/IM scheme (M→S) reveal the back-to-back QBER and SKR of 3.13% and 20 kbit/s, but only allow 6-km SSMF transmission with degraded QBER and SKR of 3.6% and 2.7 kbit/s, respectively.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7346-7359"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissipative Soliton Resonance in a V4C3Tx MXene-Based 2 μm Fiber Laser for Pulse Energy Enhancement","authors":"Yaotian Hu;Yunqi Chen;Jiayue Yin;Xiaosong Dai;Wenshu Liu;Huimin Yue;Dongsheng Wang;Chen Wei;Yong Liu","doi":"10.1109/JLT.2026.3711145","DOIUrl":"https://doi.org/10.1109/JLT.2026.3711145","url":null,"abstract":"We report, to the best of our knowledge, the first demonstration of dissipative soliton resonance (DSR) in a 2 μm thulium-doped fiber laser (TDFL)employing a low-dimensional-material-based saturable absorber (SA). This work overcomes the critical challenge of low pulse energy in conventional 2 μm mode-locked lasers by enabling direct generation of nanojoule-level pulses from a single oscillator. We also present, for the first time, a systematic study of the nonlinear optical properties of V₄C₃T_x MXene at 2 μm. The material was synthesized via selective etching and fabricated into a reflective-type SA using a drop-coating method. The SA exhibits a high modulation depth of 34.22% and a saturation intensity of 41.56 MW/cm² at 2 μm. By integrating into a ring cavity with engineered near-zero anomalous dispersion, stable DSR operation was achieved. The output pulse duration could be tuned from 45.15 ns to 51.41 ns with increasing pump power, corresponding to a maximum pulse energy of 38.2 nJ, representing a two-orders-of-magnitude enhancement compared to conventional soliton mode-locking in low-dimensional-material-based 2 μm TDFLs. This work not only validates V₄C₃T_x MXene as a high-performance SA in the 2 μm spectral region, but also establishes a practical route towards compact, high-energy ultrafast laser sources at this wavelength.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7668-7673"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Performance of Sine-Wave-Gated InGaAs Single-Photon Avalanche Diodes via Discrimination of Carrier-Specific Avalanche Signatures","authors":"Shubo Liu;Ming Shi;Xiao Zhou;Jiabao Li;Kun Hu;Chunyong Yang","doi":"10.1109/JLT.2026.3705823","DOIUrl":"https://doi.org/10.1109/JLT.2026.3705823","url":null,"abstract":"Sine-wave-gated InGaAs single-photon avalanche diodes (SPADs) show considerable promise for high-speed communication systems, but their practical improvement in performance still presents substantial challenges. This study examines the properties of avalanche signals initiated by different carrier types in a room-temperature-operated sine-wave-gated InGaAs SPAD, with the goal of optimizing performance via selective avalanche signal discrimination. Measurements reveal that compared with their smaller counterparts, larger avalanche signals initiated by photogenerated carriers demonstrate slower temporal responses and higher counts. Theoretically, this behavior is attributed to variations in avalanche multiplication initiated by photogenerated carriers produced at different longitudinal locations inside the absorption layer. Because afterpulsing carriers and dark carriers arise from different physical mechanisms and spatial regions relative to photogenerated carriers, their measured avalanche signal amplitudes exhibit correspondingly distinct differences—a result that is consistent with the proposed model. Leveraging these amplitude distinctions among carrier-triggered avalanche signals, selective discrimination was implemented, resulting in enhanced device performance. The dark count rate (<italic>DCR</i>) of the InGaAs SPAD was reduced by approximately 20%, its afterpulsing probability decreased from 8.76% to 4.5%, and the timing jitter improved from 929 ps to 784 ps at room temperature. This work introduces a distinct strategy for advancing the performance of sine-wave-gated InGaAs SPADs and provides valuable insights for the codesign of InGaAs avalanche photodiodes and signal readout circuits.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7606-7612"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Linear Spectral Analysis of SiN Microring Resonator Sensors Under Nonlinear Laser Sweeps","authors":"Wenjing Tian;Xuebing Zhang;Peter Girouard;Megha Khokhar;David Coenen;Hasan Goktas;Negin Golshani;Maliheh Ramezani;Neha Singh;Hsiao-Lun Wang;Sulakshna Kumari;Philippe Absil;Marcus Dahlem;Dongjae Shin;Ruud Oldenbeuving","doi":"10.1109/JLT.2026.3708539","DOIUrl":"https://doi.org/10.1109/JLT.2026.3708539","url":null,"abstract":"Integrated silicon nitride (SiN) micro-ring resonators (MRRs) are attractive for high-speed refractive-index sensing, where accurate and rapid interrogation of resonance motion is critical. Conventional approaches based on optical spectral analyzers and tunable lasers suffer from high complexity and an inherent trade-off between speed and accuracy. Frequency-modulated spectroscopy (FMS) using chirped lasers offers high measurement speed but is fundamentally limited by laser frequency-sweep nonlinearity, which leads to severe spectral distortions and frequency errors, particularly under high-speed and dynamic operation, rendering conventional time-to-frequency mapping invalid. In this work, we demonstrate a linear and high-speed FMS system enabled by real-time optical instantaneous frequency (OIF) estimation for dynamic spectral analysis of integrated photonic resonators. By directly tracking the laser's instantaneous frequency during strongly nonlinear sweeps, the proposed approach eliminates chirp-induced distortion and enables direct reconstruction of both static and time-varying spectral responses without relying on sweeping linearity assumptions. Using a nonlinear frequency sweep spanning 6.23 GHz within 1.25 μs, corresponding to an effective sweep speed of 39872 nm/s (4.98 GHz/μs), the system accurately tracks sinusoidal resonance motion up to 80 kHz. The method is experimentally validated using a thermally tunable SiN MRR fabricated on IMEC's iSiPP200 platform, exhibiting a loaded quality factor of 1.65 × 10⁵. The proposed system resolves ultra-small peak-to-peak phase modulations down to approximately 0.15°, corresponding to resonance shifts as small as 79 MHz, and achieves a >50% reduction in dynamic frequency error compared to conventional FMS reconstruction.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 17","pages":"7621-7628"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11589312","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148877911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}