Laser beam steering of 532†nm using a power-efficient focal plane array.

Laser beam steering is important for classical and quantum information processing. On-chip beam steering is a major motivation for developing large-scale photonic integrated circuits such as optical phased arrays. A major challenge for such arrays is to simultaneously control a large number of on-chip phase shifters, which requires a complicated analog control algorithm and rapidly increasing power consumption. We report a green light (532 nm) 1 × 16 focal plane array photonic integrated circuit with simple control and low power consumption. Fabricated on a silicon nitride platform, the focal plane array achieves angular beam steering over a 10° field of view, with ultra-low electrical power consumption (4 × 3.1 mW).

Quality evaluation of compounds in leaves of six Taxus species based on UPLC-MS/MS and chemometrics.

Introduction: Taxus species are used as medicinal plants all over the world. The leaves of Taxus species are sustainable medicinal resources that are rich in taxoids and flavonoids. However, traditional identification methods cannot effectively identify Taxus species on the basis of leaces used as raw medicinal materials, because their appearance and morphological characteristics are almost the same, and the probability of error identification increases in accordance with the subjective consciousness of the experimenter. Moreover, although the leaves of different Taxus species have been widely used, their chemical components are similar and lack systematic comparative research. Such a situation is challenging for quality assessment. Materials and methods: In this study, ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry combined with chemometrics was applied for the simultaneous determination of eight taxoids, four flavanols, five flavonols, two dihydroflavones, and five biflavones in the leaves of six Taxus species, namely, T. mairei, T. chinensis, T. yunnanensis, T. wallichiana, T. cuspidata, and T. media. Chemometric methods, including hierarchical cluster analysis, principal component analysis, orthogonal partial least squares-discriminate analysis, random forest iterative modeling, and fisher linear discriminant analysis, were utilized to differentiate and evaluate the six Taxus species. Results: This proposed method exhibited good linearity (R 2 = 0.9999-0.9972) with a lower quantification limits of 0.94-3.05 ng/mL for all analytes. The intra- and inter-day precisions were within 6.83%. Six compounds, namely, 7-xylosyl-10-deacetyltaxol, ginkgetin, rutin, aromadendrin, 10-deacetyl baccatin III, and epigallocatechin, were identified through chemometrics for the first time. These compounds can be used as important chemical markers to distinguish the above six Taxus species rapidly. Conclusion: This study established a method for determination of the leaves of six Taxus species, and revealing the differences in the chemical components of these six Taxus species.

1-Pbps orbital angular momentum fibre-optic transmission.

Space-division multiplexing (SDM), as a main candidate for future ultra-high capacity fibre-optic communications, needs to address limitations to its scalability imposed by computation-intensive multi-input multi-output (MIMO) digital signal processing (DSP) required to eliminate the crosstalk caused by optical coupling between multiplexed spatial channels. By exploiting the unique propagation characteristics of orbital angular momentum (OAM) modes in ring core fibres (RCFs), a system that combines SDM and C + L band dense wavelength-division multiplexing (DWDM) in a 34 km 7-core RCF is demonstrated to transport a total of 24960 channels with a raw (net) capacity of 1.223 (1.02) Peta-bit s-1 (Pbps) and a spectral efficiency of 156.8 (130.7) bit s-1 Hz-1. Remarkably for such a high channel count, the system only uses fixed-size 4 × 4 MIMO DSP modules with no more than 25 time-domain taps. Such ultra-low MIMO complexity is enabled by the simultaneous weak coupling among fibre cores and amongst non-degenerate OAM mode groups within each core that have a fixed number of 4 modes. These results take the capacity of OAM-based fibre-optic communications links over the 1 Pbps milestone for the first time. They also simultaneously represent the lowest MIMO complexity and the 2nd smallest fibre cladding diameter amongst reported few-mode multicore-fibre (FM-MCF) SDM systems of >1 Pbps capacity. We believe these results represent a major step forward in SDM transmission, as they manifest the significant potentials for further up-scaling the capacity per optical fibre whilst keeping MIMO processing to an ultra-low complexity level and in a modularly expandable fashion.

Generation of multi-focus abruptly autofocusing beams with adjustable focus characteristics.

This work introduces and demonstrates a method for tailoring multi-focus abruptly autofocusing beams (MFAABs) in free space. Since MFAABs are formed by superposing the wavefronts of abruptly autofocusing beams (AABs), the number, positions, and relative intensity of foci are directly and independently adjusted during the pre-design of AABs. Also, we show that the size of the light field involves the characteristics of focus, such as peak intensity, focal size, and subsequent oscillations. We apply the double-phase hologram method to generate the required complex field with a phase-only spatial light modulator in experiments. With flexible control on foci characteristics, this work may broaden potential applications of autofocusing beams.

Increased systemic immune-inflammation index can predict respiratory failure in patients with Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) is a common peripheral neuropathy with relatively heterogenous clinical manifestations. In severe cases, it can result in disabling neuromuscular symptoms and respiratory failure. In this study, we assessed whether the systemic immune-inflammation index (SII) is associated with respiratory failure in GBS patients. METHODS: We retrospectively analyzed clinicopathological data from GBS patients diagnosed in the First Affiliated Hospital of Kunming Medical University. SII was calculated based on counts of neutrophils (N), platelets (P), and lymphocytes (L). Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values for SII, N, P, and L. Univariate and multivariate logistic regression were performed to determine the ability of the SII to predict respiratory failure. RESULTS: Among the 369 GBS patients in this study, 61 (16.5%) suffered respiratory failure. Multivariate logistic regression showed that N ≥ 6.03 × 109/l, Hughes Functional Grading Scale (HFGS) score ≥ 3 at admission, and SII ≥ 863.04 × 109/l can independently predict respiratory failure in GBS patients. SII showed higher predictive ability than N, based on area under the ROC curve (0.75 vs. 0.72). CONCLUSION: SII may be a novel independent prognostic indicator of respiratory failure in GBS patients, helping physicians identify those at risk in a timely manner.

Compact devices for generating multi-focus autofocusing optical beams in free space.

We introduce a new type of optical beam that can autofocus multiple times in free space, namely, a multi-focus autofocusing optical beam. Based on the superposed caustic method, we design and construct one-dimensional autofocusing optical beams by tailoring and overlapping two paraxial accelerating optical beams. The two accelerating optical beams are shaped in cosine trajectories symmetrically, thus enabling an on-axis multi-focus property. Furthermore, we fabricate compact devices utilizing diffractive optical elements on a quartz plate patterning the required phase for generations of three-focus and four-focus autofocusing optical beams in free space. We expect that this work may bring autofocusing optical beams further potential applications in particle transporting, material processing, and lithography technology.

Prospective study of the effect of sulfotanshinone sodium combined with tirofiban on vascular endothelial function and indicators of plaque stability in elderly patients with acute coronary syndrome.

WHAT IS KNOWN AND OBJECTIVE: This study aimed to explore the effect of sulfotanshinone sodium injection combined with tirofiban on vascular endothelial function and indicators of plaque stability in elderly patients with acute coronary syndrome (ACS). METHODS: We designed a prospective study and enrolled 169 patients with ACS who were admitted to our hospital as subjects. Patients treated with sulfotanshinone sodium injection combined with tirofiban (n = 99) were allocated to the research group (RG), and the remaining patients treated with tirofiban alone were allocated to the control group (n = 70; CG). The two groups were compared in terms of treatment efficacy, adverse reactions, vascular endothelial function, changes in plaque stability indicator levels, prognosis, recurrence rate, and quality of life after the treatment. RESULTS AND DISCUSSION: Treatment response rate, SOD and ET-1 levels, and quality-of-life score were markedly lower in RG than in CG (all P < .05). The incidence of adverse reactions; levels of CD63p, CD62p and GP IIb/IIIa; changes in plaque stability indicator levels; and recurrence rate were markedly higher in RG than in CG (all P < .05). There was no significant difference in 3-year survival rate between the two groups (P > .05). WHAT IS NEW AND CONCLUSION: Compared with tirofiban alone, sulfotanshinone sodium injection combined with tirofiban had superior efficacy and safety in the treatment of ACS. It can effectively reduce recurrence rate and improve quality of life in ACS, making it a strong candidate for popular clinical application.

Construction, characteristics, and constraints of accelerating beams based on caustic design.

Caustic methods have been proposed for wavefront design to enable light beams propagating along curved trajectories, namely accelerating beams. Here we elaborate the complete construction, remarkable characteristics, and hidden constraints of these methods. It is found that accelerating beams based on the caustic design have not only a well-known curved intensity distribution but also a linear phase distribution along the caustic proportional to the curved length, as if light field indeed moved along the caustic. Moreover, with this characteristic, further light-ray analyses are implemented to illustrate the constraints of caustic design in different cases. We expect our work will clarify some confusion on the effectiveness and applicability of caustic methods, and thus facilitate the design of accelerating beams for various applications.

Generation of flat wideband chaos with suppressed time delay signature by using optical time lens.

We propose a flat wideband chaos generation scheme that shows excellent time delay signature suppression effect, by injecting the chaotic output of general external cavity semiconductor laser into an optical time lens module composed of a phase modulator and two dispersive units. The numerical results demonstrate that by properly setting the parameters of the driving signal of phase modulator and the accumulated dispersion of dispersive units, the relaxation oscillation in chaos can be eliminated, wideband chaos generation with an efficient bandwidth up to several tens of GHz can be achieved, and the RF spectrum of generated chaotic signal is nearly as flat as uniform distribution. Moreover, the periodicity of chaos induced by the external cavity modes can be simultaneously destructed by the optical time lens module, based on this the time delay signature can be completely suppressed.

Security-enhanced chaos communication with time-delay signature suppression and phase encryption.

A security-enhanced chaos communication scheme with time delay signature (TDS) suppression and phase-encrypted feedback light is proposed, in virtue of dual-loop feedback with independent high-speed phase modulation. We numerically investigate the property of TDS suppression in the intensity and phase space and quantitatively discuss security of the proposed system by calculating the bit error rate of eavesdroppers who try to crack the system by directly filtering the detected signal or by using a similar semiconductor laser to synchronize the link signal and extract the data. The results show that TDS embedded in the chaotic carrier can be well suppressed by properly setting the modulation frequency, which can keep the time delay a secret from the eavesdropper. Moreover, because the feedback light is encrypted, without the accurate time delay and key, the eavesdropper cannot reconstruct the symmetric operation conditions and decode the correct data.