Advancing large-scale thin-film PPLN nonlinear photonics with segmented tunable micro-heaters

Thin-film periodically poled lithium niobate (TF-PPLN) devices have recently gained prominence for efficient wavelength conversion processes in both classical and quantum applications. However, the patterning and poling of TF-PPLN devices today are mostly performed at chip scales, presenting a significant bottleneck for future large-scale nonlinear photonic systems that require the integration of multiple nonlinear components with consistent performance and low cost. Here, we take a pivotal step towards this goal by developing a wafer-scale TF-PPLN nonlinear photonic platform, leveraging ultraviolet stepper lithography and an automated poling process. To address the inhomogeneous broadening of the quasi-phase matching (QPM) spectrum induced by film thickness variations across the wafer, we propose and demonstrate segmented thermal optic tuning modules that can precisely adjust and align the QPM peak wavelengths in each section. Using the segmented micro-heaters, we show the successful realignment of inhomogeneously broadened multi-peak QPM spectra with more than doubled peak second-harmonic generation efficiency. The advanced fabrication techniques and segmented tuning architectures presented herein pave the way for wafer-scale integration of complex functional nonlinear photonic circuits with applications in quantum information processing, precision sensing and metrology, and low-noise-figure optical signal amplification

Distribution of QTL or genes for induction and kernel abortion.

The yellow region stands for the genes or QTL related maize haploid production.</p

QTL Identified for different abortion of endosperm and embryo of the second population in single environment.

QTL Identified for different abortion of endosperm and embryo of the second population in single environment.</p

Correlations between different types of abortion kernels.

Correlations between different types of abortion kernels.</p

Data_Sheet_1_Live Poultry Trading Drives China's H7N9 Viral Evolution and Geographical Network Propagation.pdf

<p>The on-going reassortment, human-adapted mutations, and spillover events of novel A(H7N9) avian influenza viruses pose a significant challenge to public health in China and globally. However, our understanding of the factors that disseminate the viruses and drive their geographic distributions is limited. We applied phylogenic analysis to examine the inter-subtype interactions between H7N9 viruses and the closest H9N2 lineages in China during 2010–2014. We reconstructed and compared the inter-provincial live poultry trading and viral propagation network via phylogeographic approach and network similarity technique. The substitution rates of the isolated viruses in live poultry markets and the characteristics of localized viral evolution were also evaluated. We discovered that viral propagation was geographically-structured and followed the live poultry trading network in China, with distinct north-to-east paths of spread and circular transmission between eastern and southern regions. The epicenter of H7N9 has moved from the Shanghai–Zhejiang region to Guangdong Province was also identified. Besides, higher substitution rate was observed among isolates sampled from live poultry markets, especially for those H7N9 viruses. Live poultry trading in China may have driven the network-structured expansion of the novel H7N9 viruses. From this perspective, long-distance geographic expansion of H7N9 were dominated by live poultry movements, while at local scales, diffusion was facilitated by live poultry markets with highly-evolved viruses.</p

QTL Identified for different abortion of endosperm and embryo.

QTL Identified for different abortion of endosperm and embryo.</p

The embryo abortion and different degree of endosperm abortion caused by <i>in vivo</i> haploid induction.

(a)1st endosperm aborted kernels (EnA1st), same of the kernel A in Fig 1(f); (b) 2nd endosperm aborted kernels (EnA2nd), same of the kernel B in Fig 1(f); (c) 3rd endosperm aborted kernels (EnA3rd), same of kernel C in Fig 1(f); (d) 4th endosperm aborted kernels (EnA4th), same of kernel D in Fig 1(f); (e) 5th endosperm aborted kernels(EnA5th), same of kernel E in Fig 1(f); (f) F1 ear coming from one plant of Zhengdan958 F2:3 population crossing with inducer CAU5; (g) embryo aborted kernels; (h) haploid kernels.</p

Distribution of QTL for kernel abortion related during parthenogenesis induced process in the second population (Zheng58×K22).

The circle means QTLs for the 1st endosperm abortion kernels (EnA1st); the right triangle means QTLs for the 2nd endosperm aborted kernels (EnA2nd), the equilateral triangle means QTLs for the 3rd Endosperm aborted kernels (EnA3rd), the hexagon means QTLs for the 4th endosperm aborted kernels (EnA4th), The rhombus means QTLs for the 5th endosperm aborted kernels (EnA5th), the trapezoid means QTLs for the total endosperm aborted kernels (EnA). The pentagon means QTLs for the embryo abortion kernels (EmA). The square means QTLs for the total aborted kernels (TA). The red means the QTL identified across two environments, the green means the QTL identified in Hainan environment; the white means the QTL identified in Zhengzhou environment.</p

Anova of different types of abortion kernels in both populations.

Anova of different types of abortion kernels in both populations.</p

Estimation of statistical parameters for different abortion traits.

Estimation of statistical parameters for different abortion traits.</p