A 32-channel 100 GHz wavelength division multiplexer by interleaving two silicon arrayed waveguide gratings

A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channel AWGs with200 GHz spacing and a Mach-Zehnder interferometer(MZI)with 200 GHz free spectral range.The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum,but with an identical spacing of 200 GHz.For the composed wavelength division multiplexer,the experiment results reveal 32 wavelength channels in C-band,a wavelength spacing of 100 GHz,and a channel crosstalk lower than-15 dB.

清热化瘀汤对慢性盆腔炎致病菌体外抑菌作用的研究

目的:探讨清热化瘀汤对慢性盆腔炎致病菌的体外抑菌作用。方法:制备大肠埃希菌、金黄色葡萄球菌和乙型肺炎链球菌的混合菌液。用不同浓度的清热化瘀汤对混合菌液进行抑菌实验,通过分析OD(光学密度)绝对值的变化判定混合菌液中致病菌数量变化的情况。采用牛津杯法对混合菌液进行药敏实验,测量抑菌圈直径的大小。采用TTC法对混合菌液进行抑菌实验,计算抑菌率。结果:清热化瘀汤对慢性盆腔炎致病菌的抑菌圈直径为19 mm(药敏实验结果为高敏),对慢性盆腔炎致病菌的抑菌率为73%。结论:清热化瘀汤对慢性盆腔炎致病菌的体外抑菌作用明显。

Study on the Factors Driving the Loyalty of the Customers of a Third Party Mobile Payment Platform

. In this paper, the main driving factors affecting the customer loyalty of a third party mobile payment service were chosen by combining with the actual situation of the third party mobile payment service and customer spending habits in China. The assumed relations between all affecting factors and the customer loyalty of a third party mobile payment platform were proposed, and a model for studying customer loyalty was established and also a conclusion was made through the questionnaire survey analysis data. Finally, suggestions on improving the loyalty of the customers of a third party mobile payment platform are presented.

Snapshot multi-dimensional computational imaging through a liquid crystal diffuser

Multi-dimensional optical imaging systems that simultaneously gather intensity,depth,polarimetric,and spectral information have numerous applications in medical sciences,robotics,and surveillance.Nevertheless,most current approaches require mechanical moving parts or multiple modulation processes and thus suffer from long acquisition time,high system complexity,or low sampling resolution.Here,a methodology to build snapshot multi-dimensional lensless imaging is proposed by combining planar-optics and computational technology,benefiting from sufficient flexibilities in optical engineering and robust information reconstructions.Specifically,a liquid crystal diffuser based on geometric phase modulation is designed to simultaneously encode the spatial,spectral,and polarization information of an object into a snapshot detected speckle pattern.At the same time,a post-processing algorithm acts as a special decoder to recover the hidden information in the speckle with the independent and unique point spread function related to the position,wavelength,and chirality.With the merits of snapshot acquisition,multi-dimensional perception ability,simple optical configuration,and compact device size,our approach can find broad potential applications in object recognition and classification.

High-fidelity mode scaling via topologicaloptimized on-chip metalens for compact photonic interconnection

Photonic integrated circuits(PICs)have attracted significant interest in communication,computation,and biomedical applications.However,most rely on highly integrated PICs devices,which require a low-loss and high-integration guided wave path.Owing to the various dimensions of different integrated photonic devices,their interconnections typically require waveguide tapers.Although a waveguide taper can overcome the width mismatch of different devices,its inherent tapering width typically results in a long length,which fundamentally limits the efficient interconnection between devices with a high scaling ratio over a short distance.Herein,we proposed a highly integrated on-chip metalens that enables optical interconnections between devices with high width-scaling ratios by embedding a free-form metasurface in a silicon-on-insulator film.The special geometric features endow the designed metalens with high coupling efficiency and high integration.The device has a footprint of only 2.35μm in the longitudinal direction and numerical aperture of 2.03,enabling beam focusing and collimation of less than 10μm between devices with width-scaling ratio of 11.For the fundamental transverse electric field(TE0)mode,the relative transmittance is as high as 96%for forward incidence(from wide to narrow waveguides),whereas the metalens can realize wavefront shaping for backward incidence,which can be used in optical phase arrays.This study provides new ideas for optical interconnect design and wavefront shaping in high-integration PICs.Our design approach has potential applications in directional radiators,LiDAR,on-chip optical information processing,analogue computing,and imaging.

High-performance ultra-compact polarization splitterrotators based on dual-etching and tapered asymmetrical directional coupler

High-performance ultra-compact polarization splitter-rotators(PSRs)are designed and experimentally demonstrated,using dual etching and a tapered asymmetrical directional coupler.First,two novel PSRs are designed with nanowire and subwavelength grating cross-port waveguides and verified in simulations.Then,one of the two PSRs is fabricated.Experiment results reveal that the extinction ratio is higher than 28 dB or 32 dB at 1550 nm for the launched fundamental transverse magnetic or the transverse electric modes,while the corresponding insertion loss and polarization conversion loss are 0.33 dB and 0.18 dB,respectively.