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Fano resonances with a high extinction ratio (ER) and slope rate (SR), along with controllable tuning, are highly desired for important applications such as sensing and all-optical information processing. Here, we propose and experimentally demonstrate a tunable Fano-like resonance with an ultra-high SR, based on nonlinear interference within a single chalcogenide microring resonator (MRR). By tuning the relative phase of the involved waves with an external phase shifter, the transmission spectrum is dynamically reconfigured from a symmetric Lorentzian gain peak to Fano-like or electromagnetically induced transparency (EIT)-like lineshapes. Utilizing a chalcogenide MRR with a Q-factor exceeding 106, we achieve controllable Fano resonance with a remarkable ER of up to 35.3 dB, and an ultra-high SR of 2.5 × 105 dB/nm, which is the highest one as compared to previous works. This result holds great potential for high-performance all-optical control and high-sensitivity sensing on a chip.

Polarization scrambling models (PSM) are useful in various areas of optics research. The conventional rotatable waveplate-based PSM is easy to implement physically yet exhibits limitations in model characterization. This paper develops two novel PSMs based on cascaded extrinsic and intrinsic elementary rotations of the state of polarization (SOP). The new models exhibit rich features in terms of deterministic polarization scrambling speed and tunable distribution of SOP variation rate. The development of new models also provides us with novel theoretical tools for characterizing various PSMs. We study the new models with detailed mathematical derivations and analyses, verified by extensive numerical simulations. The developed models could be useful for theoretical study and building simulation platforms for polarization testing.

A mode gain equalization inline few-mode erbium-doped fiber amplifier (FM-EDFA) is an important device in a long-distance mode division multiplexing fiber communication system. In this paper, we propose and demonstrate an FM-EDFA with low differential mode gain (DMG) developed from a hybrid mode-bases multiplexed amplification scheme. This strategy exploits the differential mode-bases gain (DMBG) between the linearly polarized (LP) and orbital angular momentum (OAM) modes with the same vector mode group to equalize the DMG of an FM-EDFA. Based on this scheme, the mode gain equalization of a 5-mode-group EDFA is achieved, and mode matching between the EDF and transmission fiber is attained without increasing the difficulty of EDF fabrication. The simulation results reveal that the maximum DMG among the 5 mode groups at 1550 nm can be reduced from 0.75 dB to 0.11 dB by switching the signal mode LP3,1 to OAM3,1 when the FM-EDFA is pumped by a fundamental mode. We fabricated an FM-EDF and characterized it by constructing a testing system that supports the multiplexing and switching of all 5 mode groups. A decrease in the DMG from 1.88 dB to 1.08 dB was experimentally demonstrated. Finally, we construct a 5-mode-group all-fiber FM-EDFA using a custom-made isolated wavelength division multiplexer, and an average mode gain above 26 dB and an average DMG of 1.79 dB over the C band are achieved.

Two chitosan oligosaccharide derivatives, VCOS and GCOS, were synthesized and explored as corrosion inhibitors, the synergistic inhibition effect of KI and VCOS was also studied. Their structures were elucidated using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance. The inhibition efficacy of VCOS+KI and GCOS on 20# steel within an 80℃, 3 wt% NaCl, CO2-saturated solution system was investigated employing various techniques, including gravimetric measurement, electrochemical analysis, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and molecular dynamics simulations. The results reveal that the inhibition efficiency of VCOS is relatively low when it acts alone. When VCOS and KI are combined, they have a good synergistic effect, and the synergistic parameter is the highest at 6.209. In the weight loss experiment, the corrosion inhibition efficiency increased with the concentration of the corrosion inhibitor. The inhibition rates of VCOS+KI and GCOS were 90.5 % and 90.2 %, respectively. The adsorption on 20# steel conformed to the Langmuir isotherm adsorption equation. The measurement results of SEM, Energy Dispersive Spectroscopy, and AFM show that VCOS+KI and GCOS adsorbed on the surface of carbon steel to form a dense inhibitor film, which effectively protected the metal substrate. According to the polarization test results, both VCOS+KI and GCOS are mixed-type inhibitors primarily exhibiting anodic inhibition, with inhibition efficiencies reaching 98.9 % and 95.1 %, respectively. Electrochemical impedance spectroscopy tests showed that with increasing inhibitor concentration and immersion time, Rctincreased and Cdldecreased, resulting in a gradual increase in inhibition efficiency and the formation of a dense and stable inhibitor film. The results indicate that VCOS+KI and GCOS are non-toxic, water-soluble, and environmentally friendly inhibitors with good anti-corrosion performance.

Delta-sigma modulation (DSM) has been considered as an effective means to replace the common public radio interface (CPRI) for the implementation of novel mobile fronthaul (MFH) architectures. However, the recent studies paid great attention on the performance optimizations of the delta-sigma modulators, which could help to enhance signal-to-noise ratio (SNR). Few of them focus on the improvement of noise immunity. In this paper, we apply three-dimensional (3D) constellations to DSM, thereby improving the noise immunity performance of the ultra-high order quadrature amplitude modulation (QAM) constellations. Moreover, addressing the huge number of constellation points in the ultra-high order constellations, we propose a novel constellation approach based on 3D-constellation partition. This approach significantly simplifies the transmission system, leading to an 8-fold improvement in processing efficiency. The experimental demonstrations were realized in a 100 GHz photonics-assisted W-band transmission system, indicating that the transmission scheme based on 3D-constellation could obtain an approximate 0.5 dB gain in receiver sensitivity compared to that using 2D-constellation. Verified by the transmission of ultra-high order DSM signals in the 15-km single-mode fiber (SMF) and 2.6-m W-band wireless link, we could achieve 262144-QAM at a rate of 17.5 Gb/s under a simple digital signal processing (DSP).

Due to the continuous growth of traffic demand, the capacity of current fiber optical networks offered by the conventional telecom bands will soon be exhausted. Bidirectional transmission, in which signals of the same wavelength are transmitted in opposite directions of a single fiber, is an attractive option for increasing the capacity of installed fiber links. However, the transmission distance and capacity of same-wavelength bidirectional links are limited by Rayleigh backscattering. Here, we present a method to improve the performance of same-wavelength bidirectional transmission by alleviating the Rayleigh backscattering induced signal distortion using phase-sensitive amplification (PSA). Relying on the phase-sensitive gain property, the optical signal-to-backscattering ratio, which dominates the received signal-to-noise ratio of the bidirectional transmission link, can be improved by at least 3 dB. Using this approach, we successfully demonstrate wavelength-division-multiplexed 16QAM same-wavelength bidirectional transmission over a 102-km G.652.D standard single-mode fiber. The proposed solution paves the way for bidirectional transmission beyond backscattering-limited capacity, enabling capacity expansion without the need for new fibers or redesigned transceivers outside of conventional bands. In addition, the concept of using the phase-dependent nature of PSA to mitigate the negative impact of Rayleigh backscattering is of interest for other physical systems that are negatively affected by backscattering.

The long-term operation feature of enzymatic biofuel cell-based self-powered biosensor (EBFC-SPB) endows them with the potential to execute dual-signal biosensing without having to integrate an extra signal acquisition device. Herein, cobalt and manganese codoped CeO2nanospheres (CoMn-CeO2NSs) with glucose-oxidase-like and peroxidase-like activities have been developed as substrate-switched dual-channel signal transduction components in EBFC-SPB for a dual-signal assay of aflatoxin B1 (AFB1). The CoMn-CeO2NSs modified with aptamer are anchored to a complementary DNA-attached bioanode of EBFC-SPB by base complementary pairing, which catalyze the glucose oxidation together with the glucose oxidase (GOx) on the bioanode. Once the AFB1 appears, CoMn-CeO2NSs will be released from the bioanode due to the binding specificity of the aptamer, resulting in a decreased catalytic efficiency and the first declining stage of EBFC-SPB. Accompanied by the introduction of H2O2, the residual CoMn-CeO2NSs on the bioanode switch to peroxidase-like activity and mediate the production of benzo-4-chlorohexadienone (4-CD) precipitate, which increases the steric hindrance and yields another declining stage of EBFC-SPB. By assessing the variation amplitudes during these two declining stages, the dual-signal assay of AFB1 has been realized with satisfying results. This work not only breaks ground in dual-signal bioassays but also deepens the application of nanozymes in EBFC-SPB.

Li-ion-based electric field control has been attracting significant attention, since it is able to penetrate deep into materials to exhibit diverse and controllable electrochemical processes, which offer more degrees of freedom to design multifunctional devices with low power consumption. As opposed to previous studies that mainly focused on single lithiation/delithiation mechanisms, we reveal three Li-ion modulation mechanisms in the same NiFe2O4spinel ferrite by in situmagnetometry, i.e., intercalation, conversion, and space charge, which are respectively demonstrated in high, medium, and low voltage range. During the intercalation stage, the spinel structure is preserved, and a reversible modulation of magnetization arises from the charge transfer-induced variation of Fe valence states (Fe2+/Fe3+). Conversion-driven change in magnetization is the largest up to 89 emu g–1, due to the structural and magnetic phase transitions. Although both intercalation and conversion exhibit sluggish kinetics and long response times, the space charge manifests a faster switching speed and superior durability due to its interface electrostatic effect. These results not only provide a clear and comprehensive understanding on Li-based modulation mechanisms but also facilitate multifunctional and multiscenario applications, such as multistate memory, micromagnetic actuation, artificial synapse, and energy storage.

Spent ternary lithium-ion batteries, containing PVDF binder and acetylene black as conductive agents, have the potential to destroy the stable layered structure of cathode materials during heat treatment due to their reducibility. However, the reduction mechanism of two of the organic components and their mixtures on cathode materials remains unclear. In this work, the in situ thermal reduction of transition metals using inherent organic components is conducted and the reduction mechanisms of mixtures are analyzed deeply. Results revealed that PVDF mainly relies on high-temperature pyrolysis to generate reducing gases along with a small amount of pyrolysis residual carbon. Acetylene black primarily achieves cathode material reduction through carbothermal reduction within a solid–solid reaction system. The temperature for the thermal reduction of PVDF is about 500 °C, which is lower than that of acetylene black (575 °C). PY-GC-MS testing confirmed that the pyrolysis products of mixtures were completely consistent with those of PVDF, indicating that PVDF and acetylene black did not chemically react during thermal reduction. Furthermore, the addition of acetylene black to PVDF had a positive effect on the thermal reduction reaction, enhancing the reduction effect. However, in mixtures with higher acetylene black content and lower PVDF content, increased PVDF emission created greater separation between acetylene black and the cathode materials, negatively affecting the solid–solid reaction and reducing the overall reduction efficiency.

This study investigates the use of peanut husk biowaste (PH) activated carbon to remove 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chlorophenol (4-CP) from water. Acid activation of PH enhances its structure, creating pores in the activated carbon. SEM, TEM, and XRD confirm the effectiveness of this process. BET analysis shows the increase in surface area from 0.775 to 547 ​m2 ​g−1for the PH and PH-AC samples. PH-AC tested against 2,4-D and 4-CP, optimizing pH, contact time, pollutant dose, PH-AC dose, and temperature for maximum adsorption efficiencies. Maximum adsorption capacity for 2,4-D and 4-CP is 165.9 and 99.4 ​mg ​g−1, respectively, higher than previous research. Kinetics, adsorption, and thermodynamic studies reveal the endothermic and spontaneous nature of the adsorption process. The adsorbent demonstrates stability and long-term applicability, with substantial adsorption capacities for four cycles. Cytotoxicity studies confirm non-toxicity and environmental friendliness of PH-AC material. These findings highlight the potential of PH-AC for wastewater treatment.

This paper demonstrates the first field trial of autonomous lightpath provisioning over a space-division multiplexing (SDM) optical network built with 16.5-km 7-core fibers. In particular, we devised an amplifier gain configuration algorithm aided by a composable quality-of-transmission (QoT) estimator. The composable QoT estimator allows per-span impairment assessment, and therefore, enables sequential gain optimization without the need for data plane trial and error. For each amplifier, the algorithm picks a solution that maximizes the overall QoT margin obtained for both in-service and newly established lightpaths. We trained the QoT estimator with data collected from the field testbed and conducted lightpath provisioning experiments under multiple scenarios (using different routing, modulation formats and baud rates). We also demonstrated automated failover operations in the cases of equipment failure and receiver filter shifting. Results show that the proposed design can accomplish lightpath configuration/failover autonomously in around 10 seconds while securing desired QoT levels.

Exosomal miRNAs are considered promising biomarkers for cancer diagnosis, but their accuracy is severely compromised by the low content of miRNAs and the large amount of exosomal miRNAs released from normal cells. Here, we presented a dual-specific miRNA’s logical recognition triggered by an entropy-driven catalysis (EDC)-enhanced system in exosomes for accurate detection of liver cancer-cell-derived exosomal miR-21 and miR-122. Taking advantage of the accurate analytical performance of the logic device, the excellent membrane penetration of gold nanoparticles, and the outstanding amplification ability of the EDC reaction, this method exhibits high sensitivity and selectivity for the detection of tumor-derived exosomal miRNAs in situ. Moreover, due to its excellent performance, this logic device can effectively distinguish liver cancer patients from healthy donors by determining the amount of cancer-cell-derived exosomal miRNAs. Overall, this strategy has great potential for analyzing various types of exosomes and provides a viable tool to improve the accuracy of cancer diagnosis.

Hinckley index (Hi) can be used to characterize the crystallinity of kaolinite. Stacking order-disorder in kaolinite can considerably affect its crystallinity. However, the correlation between Hi and stacking order-disorder in kaolinite has not been reported thus far. Herein, the correlation between stacking order-disorder in kaolinite and Hi was investigated via experiments (XRD, IR spectroscopy, TG-DSC), molecular simulation, and structure refinement. First, we experimentally discovered that the stacking order-disorder in kaolinite changed the relative position between two adjacent structural layers, mainly afecting the interlayer forces. When the kaolinite layers are orderly stacked, the interlayer force is higher and the stacking lattice energy is lower. The lattice energy of kaolinite in diferent stacking states was simulated and analyzed using first-principles calculation. It was determined that the kaolinite layers are orderly stacked when two kaolinite layers have zero shift and disorderly stacked otherwise. Finally, through structural refinements, we proposed a new crystallinity index based on stacking order-disorder in kaolinite (crystallinity index based on stacking, CIS). CIS was well fitted to Hi (R2= 0.986), indicating that kaolinite crystallinity, characterized by Hi, is essentially the ratio of orderly stacking to total stacking (the sum of ordered and disordered stacks). Furthermore, measuring Hi is difficult when kaolinite crystallinity is poor; however, CIS can be used alternatively. This study of the crystallinity of kaolinite will have important significance for its industrial application.

The security issues of passive optical networks (PONs) have always been a concern due to broadcast transmission. Physical-layer security enhancement for the coherent PON should be as significant as improving transmission performance. In this paper, we propose the advanced encryption standard (AES) algorithm and geometric constellation shaping four-level pulse amplitude modulation (GCS-PAM4) pilot-based key distribution for secure coherent PON. The first bit of the GCS-PAM4 pilot is used for the hardware-efficient carrier phase recovery (CPR), while the second bit is utilized for key distribution without occupying the additional overhead. The key bits are encoded by the polar code to ensure error-free distribution. Frequent key updates are permitted for every codeword to improve the security of coherent PON. The experimental results of the 200-Gbps secure coherent PON using digital subcarrier multiplexing with 16-ary quadrature amplitude modulation show that the GCS-PAM4 pilot-based key distribution could be error-free at upstream transmission without occupying the additional overhead and the eavesdropping would be prevented by AES algorithm at downstream transmission. Moreover, there is almost no performance penalty on the CPR using the GCS-PAM4 pilot compared to the binary phase shift keying pilot.

Beyond 100G passive optical networks (PONs) will be required to meet the ever-increasing traffic demand in the future. Coherent optical technologies are the competitive solutions for the future beyond 100G PON but also face challenges such as the high computational complexity of digital signal processing (DSP). A high oversampling rate in coherent optical technologies results in the high computational complexity of DSP. Therefore, DSP running in a non-integer-oversampling below 2 samples-per-symbol (sps) is preferred, which can not only reduce computational complexity but also obviously lower the requirement for the analog-to-digital converter. In this paper, we propose non-integer-oversampling DSP for meeting the requirements of coherent PON. Complexities of complex-valued multiplication of the proposed DSP working at 9/8-sps and 5/4-sps oversampling rates can be reduced by 44.04% and 40.78% compared to that working at the 2-sps oversampling rate, respectively. A 400-Gb/s-net-rate coherent PON based on digital subcarrier multiplexing was demonstrated to verify the feasibility of non-integer-oversampling DSP. There is almost no penalty on the receiver sensitivity when non-integer-oversampling DSP is adopted. In conclusion, non-integer-oversampling DSP shows great potential in the future coherent PON.

Inter-symbol-interference (ISI) and nonlinear distortions are the major impairments in high-speed short-reach intensity modulation and direct detection (IM-DD) systems. Linear ISI can be well addressed with linear equalizer cascaded maximum likelihood sequence estimation (MLSE), while the nonlinear distortions cannot be effectively compensated in this manner. In this article, a low complexity nonlinear compensation scheme jointing Tx look-up-table (LUT) and Rx LUT based nonlinear MLSE is proposed to fully eliminate the system nonlinear distortions. The effectiveness of the proposed scheme is experimentally verified in 150/165/180 Gbit/s PAM8 systems over 20-km single-mode fiber transmission at O-band. The experimental results of the 150/165 Gbit/s PAM-8 system demonstrate that the proposed scheme exhibits 1∼2 dB receiver sensitivity improvement compared to the scheme only with one LUT on the transmitter or receiver at the bit error rate (BER) of 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10−3. In addition, the proposed scheme can support the transmission of 180 Gbit/s PAM-8 signal over 20-km SSMF with the BER below the 7% HD-FEC threshold. Finally, a nonlinear reduced state MLSE (RS-MLSE) based on joint Tx and Rx LUT is also investigated to reduce the complexity of the MLSE decoder. The results show that it can reduce 98.44% multiplications, 98.44% additions, and 84.38% comparisons while with a negligible BER performance penalty.

We propose a center-raised ring-core fiber (RCF), which can support 5-mode-group-multiplexed multiple-input and multiple-output free (MIMO-free) transmission. The center region in the index profile of the ring core is lifted from silica to enlarge the separation of lower-order mode groups (MGs) so that the RCF supports more weakly-coupled MGs. Moreover, the 5-MG RCF was fabricated, and the loss of each mode can maintain about 0.3 dB/km. The minimum effective index separation between the adjacent radial first-order MGs is 1.35 $\times\; 10^{-3}$. In addition, we also adopted the swept-wavelength interferometry (SWI) technique to evaluate the coupling coefficients between the radial first-order MGs in the RCF, which are all less than −30 dB/km. Furthermore, it is demonstrated that 5 MGs modulated by 32-Gbaud QPSK signals are multiplexed and transmitted in a 10-km RCF MIMO-free transmission system. To the best of our knowledge, it is the largest number of the multiplexed radial first-order MGs of the RCF at present. At the same time, we also verified the wavelength division multiplexing (WDM) performance of the fiber in the C-band. In the future, in order to further increase the transmission capacity of this fiber, 4 × 4 MIMO and dense WDM in C+L bands can be utilized. Therefore, we believe that this fiber can increase the number of weakly-coupled MGs to increase the single-fiber transmission capacity of mode division multiplexing (MDM).

High spectral efficiency (SE) transmission is a critical topic for next-generation ultra-high-speed optical networks, particularly for intensity-modulation with direct-detection (IM-DD) systems where the degree of freedom for data delivery is severely constrained. In this article, two high SE transmission approaches, namely fast than Nyquist (FTN) and high order modulation formats (HoMF) signaling, are experimentally demonstrated for peak-power constrained IM-DD systems. For FTN signaling, not only the sequence decoder based on M-Viterbi algorithm (M-VA), but also colored noise suppressed processing including partial response precoding (PRP), partial response equalization (PRE), nonlinear differential precoding (NLDP), Tomlinson-Harashima precoding (THP), and simplified THP (SfTHP) are investigated cooperatively to enhance the robustness of the system against inter-symbol interference (ISI) caused by acceleration. For HoMF signaling, probabilistic shaping (PS) with Maxwell Boltzmann (MB) and inverse MB distributions are discussed for rate adaptation. In a slight bandwidth-limited IM-DD system, although the PRE or SfTHP coupled with M-VA decoder enabled 56 GBaud FTN PAM4 signal with 0.7 compression factor is successfully transmitted over 2-km single-mode fiber (SMF) with BER under the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10−3, a 39.2 GBaud MB-PS PAM8 with the same spectral efficiency, 2/0.7, shows about 1.8 dB receiver sensitivity improvement. However, in an IM-DD system with 32 GHz cut-off bandwidth and severe in-band degradation, the maximum achievable transmission rate of FTN PAM4 and PS-PAM8 are 162 Gb/s and 145 Gb/s, corresponding to 2.53 and 2.266 bits/symbol SEs, respectively, at BER of 3.8 × 10−3. According to the experimental results, the proposed colored noise suppressed FTN signaling offers significant potential as a solution for bandwidth-starved high-speed IM-DD systems.

Model generalization characterizes the sustainability of machine learning (ML) designs applied to novel system states and therefore plays a vital role toward the realization of cognitive networking. In this paper, we present a composable ML framework (namely, CompML), aiming at generalizing ML-aided cognitive applications for optical networks. CompML makes use of three basic functional modules, i.e., the Loading, Recursion, and Readout modules, to model the loading/initialization processes (e.g., the launch of a signal), extract cumulative features by recursive operations, and produce model inferences, respectively. By the composition of the three modules and adoption of an end-to-end training mechanism, CompML allows for generalizing multiple tasks of the same domain [e.g., quality-of-transmission (QoT) estimation for different lightpaths]. We perform case studies of CompML on QoT estimation and nonlinearity compensation using both simulation and experimental data. Results show the superior generalization ability of CompML compared with the baselines, achieving mean absolute error (MAE) for generalized signal-to-noise ratio (GSNR) prediction error of below 1.06 dB for unseen lightpaths and up to 3 dB ${Q}$-factor improvement for nonlinearity compensation.

Phase fading is a critical issue that hinders phase retrieval in the phase-sensitive optical time-domain reflectometry (ϕ-OTDR). This paper introduces a novel approach for mitigating fading effects by implementing a three-layer structure multiplexing (TLSM) technique. The TLSM method is based on multiple pulses detection, trace decomposition and spatial multiplexing to create independent sub-components, which are then re-combined by rotated vector summation (RVS) method. Additionally, a Kalman filter is employed to eliminate the phase mismatching among these sub-components. Experimental results demonstrate a fading-free interrogation in a 40-km fiber sensing range and distorted vibration signal can be corrected. The demodulated amplitude trough could be improved by 35.2 dB. Large-sample testing confirms no occurrence of fading throughout the entire 40 km sensing range, indicating the high reliability of this method.

Chromatic dispersion estimation (CDE) and timing error detection (TED) are essential components of digital signal processing for coherent optical communication systems. Despite the extensive research conducted in coherent single-mode fiber transmission systems, traditional algorithms are less efficient or ineffective when operating in few-mode fiber transmission. We develop new cyclostationary-based methods for CDE and TED, suitable for mode-division multiplexing systems employing weakly coupled orbital angular momentum fiber. The novel methods feature strong resistance to polarization mode dispersion and mode coupling. Simulations and experimental evaluations confirm the superior performance of the proposed methods.

Photocatalysis, a promising technology to convert solar energy to chemical energy, is expected to relieve the global energy shortage and environmental pollution and therefore has attracted widespread recent research attention. Metal-organic frameworks (MOFs), a class of micro-mesoporous hybrid material constructed from metal or metal nodes interconnected with multi-dentated organic linkers, have recently been demonstrated to be promising photocatalysts for a variety of reactions relevant to environmental and energy concerns due to their unique structure and characteristics. Considering that MOF-based photocatalysis burgeoned rapidly during the past several years, and with an aim to develop more efficient MOF-based photocatalytic materials, it is still necessary to summarize the strategies already reported to improve the performance of MOF-based photocatalytic materials, even though several excellent reviews on MOF-based photocatalysis have already been published. In this review, four structural engineering strategies to improve the efficiency of MOF-based photocatalysis have been summarized. These strategies include metal doping, ligand functionalization, the fabrication of ultrathin 2D MOFs, and defect engineering. These methods aim to enhance light absorption, improve charge separation and transportation, and create more catalytic active sites. Personal opinions on the opportunities, challenges, and developing trends of MOF-based photocatalysis were addressed. This review aims to provide guidance for the rational development of advanced MOF-based photocatalysts by elucidating the inherent relationship between their structural properties and catalytic activity.

A new method of demodulation of salinity and temperature (ST) two-parameter sensor based on tilted fiber Bragg grating (TFBG) and Fabry–Perot structure using a double-branch convolutional neural network (CNN) with dense connected blocks is proposed. A total of 4344 spectral samples were collected when the sensor was immersed in sodium chloride solution with different salinities and temperatures, in an attempt to train and test the CNN model. Experimental results showed that the well-trained CNN model could realize real-time and high-precision demodulation of the ST dual-parameter sensor. The mean absolute errors (MAEs) of ST are 0.207 ‰ and 0.11 °C, respectively, and the determination coefficients are 85.51% and 99.96%, respectively. The predicted ST value of sodium chloride solution by the proposed characterization approach is consistent with the truth value, which shows great potential applications of such a sensor for high-precision double-parameter measurement.

In this article, a joint application of simplified Tomlinson-Harashima precoding (THP) and M-log-maximum a posteriori probability (M-log-MAP) decoder at transceivers is proposed for low complexity faster than Nyquist (FTN) 4-ary pulse amplitude modulation (PAM4) signaling. A THP with only two taps is applied at the transmitter for FTN-induced inter-symbol interference elimination and equalization-induced noise amplification issue mitigation, which effectively relieves the burden of the receiver. At the receiver, a low complexity M-log-MAP decoder is equipped for residual impairments cancellation, thus a feedback channel is not required to accurately obtain the channel state information for the transmitter. Taking advantage of this collaborative approach, the proposed scheme performs much better than applying the two schemes separately. We experimentally demonstrate the proposed scheme in 70, 75, and 80 GBaud PAM4 systems with a 32-GHz brick-wall filter, corresponding to 0.914, 0.853, and 0.8 FTN compression factor, respectively. The results show that the 80 GBaud PAM4 signal is successfully transmitted over 2-km single mode fiber with the bit-error-rate (BER) under the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10−3. It is also observed that the proposed scheme shows about 0.7 dB receiver sensitivity improvement compared to the error propagation-free decision feedback equalizer, namely the performance upper bound of the THP, at BER of 7% HD-FEC threshold in a 75 GBaud FTN PAM4 system. According to the experimental results, the proposed scheme is a promising solution for bandwidth-starved low-cost intra-datacenter interconnect.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare inflammatory disorder of bone, joints, and skin, with various stages of bone lesions including inflammation and bone marrow fibrosis. Because the inflammation-induced fibrosis and bone marrow fibrosis are important features in SAPHO syndrome, we undertook a prospective investigation to evaluate whether PET/CT with 68Ga-DOTA-FAPI-04, a novel PET agent targeting fibroblast activation protein, was useful in the evaluation of the patients with SAPHO syndrome.

Reproductive hormones play vital roles in reproductive health and can be used to assess a woman’s ovarian function and diagnose diseases associated with reproductive endocrine disorders. As these hormones are important biomarkers for reproductive health monitoring and diagnosis, a rapid, high-throughput, and low-invasive detection and simultaneous assessment of the levels of multiple reproductive hormones has important clinical applications. In this work, a quadruplex ultrasensitive immunoassay was developed for simultaneous assessment of 4 human reproductive hormone proteins (follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and anti-Müllerian hormone (AMH)) in a variety of human biofluid samples. This assay takes advantage of single-molecule imaging of microwell arrays and capture antibody beads as a reaction interface to construct multiplex bead array immunoassays. The analyte-bound beads can easily be parsed to individual wells and detected via fluorophores, emitting distinct wavelengths associated to the beads. As a result, this proposed quadruplex immunoassay exhibits four good 4-parameter logistic calibration curves ranging from 2.7 to 2000, 1.6 to 1200, 1.8 to 1300, and 0.3 to 220 pg/mL with limits of detection of 0.32, 0.28, 0.14, and 0.02 pg/mL for FSH, LH, PRL, and AMH, respectively. Furthermore, the developed quadruplex immunoassay was used to test clinical venous serum samples where it showed remarkable consistency with clinical test results in methodological comparison and the diagnosis of polycystic ovary syndrome. In addition, we successfully applied the ultrasensitive capability of this assay to the simultaneous testing and evaluation of four proteins in fingertip blood as well as urine samples, in which the urinary AMH level (1.42–156 pg/mL) was measured and assessed quantitatively for the first time.

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Energy storage technology is one of the effective means to promote the consumption of new energy. It has the advantages of improving the flexibility and stability of power grid. Energy storage plays an important role in improving the peaking and valley filling function of the load side of the power grid. Based on the two-stage topology of the energy storage system, this paper establishes the mirror model of the practical application engineering of the energy storage system, and uses the data-driven method to establish the energy storage battery model. On this basis, the multi-objective control strategy is adopted for the peak regulating power of the energy storage system and the load state balance of the battery. The support vector machine algorithm is used to predict the daily load data of the power grid, and the constant power algorithm is proposed to control the battery control node signal. Finally, taking the battery compartment of the energy storage system as the simulation object, the effectiveness of the proposed control strategy is verified, which provides a theoretical basis for the topic research.

Chalcogenide glasses (ChGs) have recently emerged as enabling materials for building reconfigurable nanophotonic devices by employing their refractive index changes associated with photosensitive effects. In particular, the availability of low-loss thin-film ChGs and the realization of high-Q microresonators provide exciting opportunities for integrated photonics. So far, the ChG photonic devices are predominately operated in the classical optics regime. In this work, we present the realization on-chip bright photon-pair quantum light sources via spontaneous four-wave mixing in a high-Q microring resonator fabricated on the newly developed ChG Ge25Sb10S65platform. The emission wavelength of the photon-pair source can be continuously tuned across a double-free spectral range in a reconfigurable manner. Our work serves as a starting point to fully unleash the potential of exploiting ChGs for developing reconfigurable integrated quantum photonic devices.

Sensing systems based on cholinesterase and carboxylesterase coupled with different transduction technologies have emerged for pesticide screening owing to their simple operation, fast response, and suitability for on-site analysis. However, the broad spectrum and specificity screening of pyrethroids over organophosphates and carbamates remains an unmet challenge for current enzymatic sensors. Human serum albumin (HSA), a multifunctional protein, can promote various chemical transformations and show a high affinity for pyrethroids, which offer a route for specific and broad-spectrum pyrethroid screening. Herein, for the first time, we evaluated the catalytic hydrolysis function of human serum albumin (HSA) on the coumarin lactone bond and revealed that HSA can act as an enzyme to catalyze the hydrolysis of the coumarin lactone bond. Molecular docking and chemical modifications indicate that lysine 199 and tyrosine 411 serve as the catalytic general base and contribute to most of the catalytic activity. Utilizing this enzymatic activity, a broad specific ratiometric fluorescence pyrethroids sensing system was developed. The binding energetics and binding constants of pesticides and HSA show that pyrethroids bind to HSA more easily than organophosphates and carbamates, which is responsible for the specificity of the sensing system. This study provides a general sensor platform and strategy for screening pesticides and reveals the catalytic activity of HSA on the hydrolysis of the coumarin lactone bond, which may open innovative horizons for the chemical sensing and biomedical applications of HSA.

We report an experimental observation on the ultraslow optical solitons (USOSs) and vortex solitons (VSs) in a room-temperature, highly resonant atomic system via the electromagnetically-induced transparency. We show that when the input power of a probe laser exceeds a threshold, the probe beam can form USOSs and VSs, whose wave shapes are nearly invariant during propagation due to the exact balance between the transversal diffraction and self-focusing Kerr nonlinearity. We also show that optical solitons and VSs have an ultraslow propagation velocity of 1 0 − 5 c (with c the speed of light in vacuum) and can be generated at a low light power of several microwatts. In addition, we provide theoretical analysis and carry out direct simulations, which agree well with the experimental results. Our findings pave the way for the generation of USOSs and VSs in room-temperature atomic systems and are useful for various applications in optical information processing and transmission. [Display omitted] • We observe optical and vortex solitons in a room-temperature atomic gas under EIT • We rank the generation powers of solitons by tracing their transverse sizes • We show solitons are generated at weak power and propagate at ultraslow velocity [ABSTRACT FROM AUTHOR]

Invasion and metastasis dominate tumor progression, causing a substantial proportion of cancer-related deaths. However, the efficacy of current antimetastatic treatments is hampered by the dearth of targeted therapeutics. Recently developed synthetic-receptor toolkits offer potential for artificially regulating cellular behavior. However, to the best of our knowledge, none has yet successfully suppressed tumor metastasis in vivo. Here, we report the first extracellular pH (epH)-driven DNA nanodevice for use in antimetastatic treatment in vivoby manipulating heterogeneous receptors on the tumor cell surface. This DNA nanodevice was constructed by partially locking tumorigenic receptor-specific aptamers with two i-motifs. Acidic extracellular pH induced dynamic allosteric reassembly within the nanodevice. The restructured nanodevice enabled oligomerization of c-Met and transferrin receptor, which inhibited tumor metastasis by blocking the hepatic growth factor (HGF)/c-Met signaling pathway. A suppressive efficacy of 86.25% was verified in an early hepatocarcinoma-pulmonary-metastasis mouse model. Such impressive antimetastatic efficacy suggests an efficient paradigm for developing adaptive antimetastatic therapeutics.An extracellular pH-actuated DNA nanodevice was developed as an antimetastatic inhibitor to suppress tumor metastasis in vivo by selectively blocking hyperactive receptor signaling.

•Based on neoadjuvant therapy containing pyrotinib, an anthracycline-free regimen can yield pCR rates no less favorable than those of anthracycline-containing regimens.•Platinum-containing, long-cycle taxane regimens appear to achieve superior efficacy under anthracycline-removed conditions.•Estrogen receptor (ER) status and HER2 status were independent predictors of tpCR.

Space division multiplexing (SDM) technology has become a research hotspot, which can increase the transmission capacity extensively and is supposed to be the next generation of the optical communication technology. Although it has been demonstrated technically in the laboratory, SDM based on multicore optical fiber still lacks of convinced field trails as demonstration and verification to commercialize such technology. In this work as a field test, we deployed a seven-core optical fiber cable for application in the practical scenarios and successfully demonstrated large capacity SDM communication system, reaching a capacity of 234 Tb/s (net 187.49 Tb/s) and achieving the capacity-distance product of 61.87 Pb/s·km (net 49.50 Pbit/s·km) in one strand of fiber just in C band. To our knowledge, it is the largest capacity in the world based on the deployed SDM multicore optical fiber cable. Additionally, we further showed the utilization in sensing that monitors the traffic surrounding the deployed seven-core fiber cable. It is knowledgeable that SDM technology requires plenty of evident verifications to overcome technical and engineering issues prior to practical deployment, and the successful field test with promising results shows its great potential of employing SDM technology in a demand of large capacity and smart city, moving it toward commercialization.

Photonic integrated sensing and communication technology based on optical fibers has recently attracted great research attention. In particular, distributed acoustic sensing (DAS) with telecommunication fibers is an emerging technology in the research areas of geology and seismology. With the massive deployment of telecommunication submarine cables, it provides an effective and low-cost approach for studying various oceanic geological and seismic activities. Though there have been some demonstrations of using DAS with submarine cables for the oceanic and geological analysis, no systematic analysis of the method has been presented, especially the signal processing techniques employed for the study. In this work, we discuss the signal processing procedure adopted to carry out seismic analysis using data obtained with the underwater DAS in detail, including the preprocessing of raw DAS data, the seismic recognition after feature extraction and event classification, and the seismic analysis of localization and magnitude estimations. Based on these signal processing methods, we successfully detect and analyze different seismic activities with our underwater DAS testbed, which utilizes the telecommunication submarine cable between two islands in the Pearl River estuary area of South China Sea.

Optical frequency combs have revolutionized spectral measurement technologies, such as dual-comb spectrometers, for fast and accurate spectroscopic measurements over broad spectral ranges. Moreover, chip-scale frequency combs based on microresonators are revolutionizing laser spectroscopy due to their compact size, low cost, and low power consumption, which offer a promising solution for integrated optical sensing applications by replacing costly bulk optical sensing components. Developing new attractive photonic materials for integrated microcomb is critical to realizing chip-based microcombs with high efficiency, broad bandwidth, and low pumping power. In this tutorial, we present novel chalcogenide chip-based microcombs for broadband laser spectroscopy. The integrated chalcogenide microresonators on silicon wafers are achieved using a home-developed chalcogenide glass (Ge25Sb10S65) with ultra-wide transmittance window, high Kerr nonlinearity, and low thermo-optic coefficient. Two fabrication processes of high quality-factor integrated chalcogenide microresonators with different core-cladding structures operating in the telecom and mid-infrared (MIR) regions, respectively, are introduced. Combined high nonlinearity with lithographically controlled flexible dispersion engineering of the chalcogenide microresonators, we have realized the versatile Kerr microcombs generation and physical mechanism, including bright soliton microcomb, dark-pulse microcomb, Raman-Kerr microcomb, broadband Kerr microcomb and the future opportunity of the MIR Kerr comb. In addition, we review the most potent examples of dual-comb spectroscopy applications for molecular characterization and laser ranging with ultra-high sensitivity and high accuracy and discuss the challenges of realizing MIR microcombs with high performance and ultracompact footprint for laser spectroscopy.

Bandwidth limitation introduced inter-symbol interference (ISI) is the major impediment for high baud rate intensity modulation and direct detection (IM/DD) system with commercial devices. Least mean square (LMS) criterion based feedforward equalizer (FFE) is the most common method to eliminate ISI in single-carrier system. However, there is a tradeoff between the residual ISI and enhanced noise when the system bandwidth is severely limited. Although a post filter (PF) followed by maximum likelihood sequence estimation (MLSE) can suppress the enhanced noise effectively, the residual ISI left by post-FFE will degrade the system performance as the subsequent MLSE only handles ISI introduced by PF. In this paper, an adaptive partial response equalization realized by a channel-shortening filter (CSF) is investigated, which is combined with MLSE. As the target of CSF is a partial response signal with desired low-pass feature, the noise will not be enhanced in this scheme. And the residual ISI with determined response can be fully solved by MLSE. The performance of CSF based MLSE (CSF-MLSE) is evaluated and compared to PF based MLSE (PF-MLSE) in 60/70/75Gbaud four-level pulse amplitude modulation (PAM-4) system with 10-dB bandwidth of 16.2 GHz. The experimental results show that CSF-MLSE has a better capability of ISI elimination compared to PF-MLSE. The bit error rate (BER) can be reduced from 7.4 × 10−3 to 4 × 10−3 and from 3 × 10−2 to 1 × 10−2 for 70Gbaud and 75Gbaud in optical back-to-back (OBTB) transmission. To further compensate the system nonlinear impairments, several nonlinear MLSE (NL-MLSE) techniques assisted by look-up table (LUT) or Volterra filter are proposed and investigated in this paper. The BER of 75Gbuad PAM-4 can be below 3 × 10−3 after using NL-MLSE schemes.

It is foreseeable that the 100 Gb/s/$\lambda$ and beyond passive optical network (PON) will be required in future optical access networks to meet the explosive growth of data traffic. The coherent optical systems could be a promising solution for the future beyond 100 G PON. Coherent PON using digital subcarrier multiplexing (DSCM) can provide flexible bandwidth allocation to a large number of access subscribers by dividing subcarriers of the DSCM signal into time slots for time-and-frequency division multiple access. When the optical network unit is allocated a new subcarrier, digital signal processing (DSP) should converge fast in the allocated time slot to ensure a low handoff latency for real-time bandwidth allocation. However, the traditional coherent DSP is hard to realize fast convergence due to blind and complex algorithms. In this paper, we design a specific training sequence (TS) structure and propose data-aided DSP to achieve fast convergence for coherent PON. The feasibility of the proposed scheme is experimentally verified in an 8 Gbaud/SC×8 SCs 400 Gb/s-net-rate coherent PON using DSCM with 16 quadrature amplitude modulation. The experimental results show that fast convergence is jointly realized by the proposed TS structure and data-aided DSP using a 416-symbol TS with a 52 ns duration. The receiver sensitivity at the 20% soft-decision forward error correction limit is approximately $\mathbf{-27}$ dBm and an optical power budget of about 35.5 dB is achieved with a booster amplifier.

Recently, orbital angular momentum (OAM) multiplexing has attracted much attention for providing an exponential growth in optical fiber capacity. As an irreplaceable component to promote long-haul OAM mode fiber transmission system, the on-line OAM mode-multiplexed fiber amplifier need to be developed. In this paper, we propose a Gaussian-like erbium doping distribution design method for ring-core erbium doped fiber (RC-EDF) to optimize the differential modal gain (DMG), which can reduce the fabrication complexity of the fiber preform. With a good match with original design, the fabricated RC-EDF was characterized by all the supporting four OAM modes ($\vert l \vert$ = 1, 2, 3, 4) multiplexed amplification, which achieves an ultra-low DMG less than 0.3 dB at 1550 nm. The gain is above 15 dB and DMG is less than 1.2 dB for four OAM modes across the C-band under a 500 mW pump power. As a proof for transmission, 32 channels (8 wavelengths × 4 OAM modes) carrying 32-Gbaud quadrature phase-shift keying (QPSK) OAM modes multiplexed-WDM transmission over the OAM-EDFA is demonstrated. The proposed OAM-EDFA with the average OSNR penalties of 0.34 dB may promote the practical implementation for the long-haul OAM modes fiber transmission system.

Determining how to add more signal channels without enlarging the cable volume is continually an issue in managing submarine cables. To improve the cost per bit and the power efficiency, space division multiplexing (SDM) is regarded as a promising solution that could be used to address optical density and cable capacity challenges regarding submarine cables. In this study, we focus on angular momentum (OAM) modes supporting few-mode ring-core fiber (RCF) solutions for submarine cables. Considering the inhibition of the hydrogen loss for the submarine cable, we propose a center-region-lifted 3-OAM-mode-group supporting RCF (abbreviated to 3-OAM-MG RCF) with a core-cladding index contrast of 0.6${\%}$, and meanwhile we also design and fabricate a matched 3-OAM-MG erbium-doped fiber (EDF). To confirm the short-haul transmission ability, we conduct a wavelength/mode/polarization division multiplexing (WDM-MDM-PDM) transmission test through a 25.3-km 3-OAM-MG RCF, where the coupled modes inside MG are demultiplexed by using 2 × 2 multiple-input multiple-out (MIMO) equalization. The transmission capacity is approximately 35 Tbit/s and the bit error rates (BERs) of all the channels are less than 2.4$\times 10^{-2}$. For the application scenario of long-haul submarine communication, a cascade WDM-MDM transmission system consisting of 3-OAM-MG RCF and 3-OAM-MG EDF is set up, which makes the BERs of all the mode and wavelength channels below the 20${\%}$ soft-decision forward error correction (SD-FEC) threshold. It indicates that data-carrying OAM mode multiplexing transmission has potential application in a long-haul submarine cable system.

In this paper, a channel response dependent noise shaping (CRD-NS) technique is proposed and experimentally demonstrated for the pre-equalized discrete multi-tone (DMT) signal transmission in intensity modulation and direct detection (IM/DD) system with a low-resolution digital-to-analog converter (DAC). Compared with traditional NS technique, the proposed CRD-NS technique can bring signal-to-quantization noise ratio (SQNR) improvement and solve the unevenly distributed SQNR problem in pre-equalized DMT signal induced by residual quantization noise without introducing additional computational complexity. Transmission and reception of 100 Gb/s 16 quadrature amplitude modulation (QAM)-DMT signal generated by a 3-bit DAC are experimentally demonstrated to verify the effectiveness of the proposed CRD-NS technique. The experimental results show that the bit-error ratio (BER) performance of 100 Gb/s 16 QAM-DMT signal with CRD-NS technique outperforms the corresponding signal with traditional NS technique. Compared with digital resolution enhancer (DRE) technique, in which channel response is also considered, the CRD-NS technique shows a similar noise shaping capability with DRE in pre-equalized DMT signal transmission, while the computational complexity can be significantly reduced, the number of real multiplications per sample is reduced from 81 to 7.

Timing recovery is critical for synchronizing the clocks at the transmitting and receiving ends of a digital coherent communication system. The core of timing recovery is to determine reliably the current sampling error of the local digitizer so that the timing circuit may lock to a stable operation point. Conventional timing phase detectors need to adapt to the optical fiber channel so that the common effects of this channel, such as chromatic dispersion (CD) and polarization mode dispersion (PMD), on the timing phase extraction must be understood. Here we exploit the cyclostationarity of the optical signal and derive a model for studying the CD and PMD effect. We prove that the CD-adjusted cyclic correlation matrix contains full information about timing and PMD, and the determinant of the matrix is a timing phase detector immune to both CD and PMD. We also obtain other results such as a completely PMD-independent CD estimator, etc. Our analysis is supported by both simulations and experiments over a field implemented optical cable.

The coupling between aryl halides and thiols to synthesize aryl thioethers viathe formation of a C–S bond is an important reaction. In this manuscript, a Pd/ZnIn2S4nanocomposite obtained viaphotoreduction of PdCl2(CH3CN)2in the presence of ZnIn2S4was found to be an efficient bifunctional catalyst to realize the coupling reaction between thiophenols and aryl halides (X = Br and I) to yield aryl thioethers. A mechanism study reveals that the reaction involves the light-initiated generation of thiyl radicals as important intermediates. This reaction protocol can be applied to a wide range of substrate scopes, with moderate to excellent yields for the desired thioethers. This study provides a facile, green and economic strategy for the synthesis of aryl thioethers under mild conditions. This work also highlights the great potential of semiconductor-based photocatalysis in light-initiated organic syntheses.

In many hydro plants, analysis of hydro turbine generator sets (HTGS) is mainly carried out by plant personnel manually. However, the results of such analysis are not always satisfactory, and [...]