851 research outputs found
SOI thermo-optic modulator with fast response
No full textSilicon-on-insulator (SOI) technology offers tremendous potential for integration of optoelectronic functionson a silicon wafer. In this letter, a 1 * 1 multimode interference (MMI) Mach-Zender interferometer(MZI) thermo-optic modulator fabricated by wet-etching method is demonstrated. The modulator has anextinction ratio of -11.0 dB, extra loss of -4.9 dB and power consumption of 420 mW. The response timeis less than 30μs
High-speed electrooptical VOA integrated in silicon-on-insulator
No full textIn this paper, we present simulation results of an electrooptical variable optical attenuator (VOA) inte-grated in silicon-on-insulator waveguide. The device is functionally based on free carriers absorption toachieve attenuation. Beam propagation method (BPM) and two-dimensional semiconductor device simu-lation tool PISCES-Ⅱ were used to analyze the dc and transient characteristics of the device. The devicehas a response time (including rise time and fall time) less than 200 ns, much faster than the thermoopticand micro-electromechanical systems (MEMSs) based VOAs
sj-pdf-1-wso-10.1177_17474930211040923 - Supplemental material for Basilar Artery Occlusion Chinese Endovascular Trial: Protocol for a prospective randomized controlled study
No full textSupplemental material, sj-pdf-1-wso-10.1177_17474930211040923 for Basilar Artery Occlusion Chinese Endovascular Trial: Protocol for a prospective randomized controlled study by Chuanhui Li, Chuanjie Wu, Longfei Wu, Wenbo Zhao, Jian Chen, Ming Ren, Chen Yao, Xiaoyan Yan, Chongya Dong, Haiqing Song, Qingfeng Ma, Jiangang Duan, Yunzhou Zhang, Hongqi Zhang, Liqun Jiao, Yuping Wang, Tudor G Jovin, Xunming Ji and on behalf of the BAOCHE Investigators in International Journal of Stroke</p
Temperature Dependence of Characteristics for Multimode Interference Based 3-dB Coupler in SOI
No full textThe temperature dependence of characteristics for multimode interference (MMI) based 3-dB coupler in silicon-on-insulator is analyzed, which originates from the relatively high thermo-optic coefficient of silicon. For restricted interference 3-dB MMI coupler, the output power uniformity is ideally 0 at room temperature and becomes 0. 32 dB when temperature rises up to 550 K. For symmetric interference 3-dB MMI coupler, the power uniformity keeps ideally 0 due to its intrinsic symmetric interference mechanism. With the temperature rising, the excess loss of the both devices increases. The performance deterioration due to temperature variety is more obvious to restricted interference MMI 3-dB coupler, comparing with that of symmetric interference MMI 3-dB coupler
Design and Fabrication of Ultracompact 3-dB MMI Coupler in Silicon-on-Insulator
No full textAn ultracompact 3-dB coupler is designed and fabricated in silicon-on-insulator,based on 12 line tapered multimode interference(MMI) coupler.Comparing with the conventional straigth MMI coupler,the device is-40% shorter in length.The device exhibits uniformity of 1.3dB and excess loss of 2.5d
SOI Waveguides Fabricated by Wet-Etching Method
No full textSOI waveguides fabricated by wet-etching method are demonstrated. The single mode waveguide and 1×2 3dB BBI splitter are analyzed and designed by three dimensional beam propagation method to correct the error of effective index method and guided mode method. The devices are fabricated. Excellent performances, such as low propagation loss of -1.37dB/cm, low excess of -2.2dB, and good uniformity of 0.3dB, are achieved
Does Health Insurance Coverage Lead to Better Health and Educational Outcomes? Evidence from Rural China
No full textUsing 2006 China Agricultural Census (CAC), we examine whether the introduction of the New Cooperative Medical System (NCMS) has affected child mortality, maternal mortality, and school enrollment of the 6-16 years olds. Our data cover 5.9 million people living in eight low-income rural counties, of which four adopted the NCMS by 2006 and four did not adopt it until 2007. Raw data suggest that enrolling in NCMS is associated with better school enrollment and lower mortality of young children and pregnant women. However, using a difference-in-difference propensity score method, we find most of these differences are driven by the endogenous introduction and take-up of NCMS, and out method overcomes classical propensity score matching's failure to address the selection bias. While the NCMS does not affect child mortality and maternal mortality, it does help improve the school enrollment of six-year-olds.
Multiferroic CoFe2O4-BiFeO3 core-shell nanofibers and their nanoscale magnetoelectric coupling
No full textMultiferroic CoFe2O4-BiFeO3 (CFO-BFO) core-shell nanofibers were synthesized by coaxial electrospinning. The spinel structure of CFO and perovskite structure of BFO were confirmed by x-ray diffraction and high-resolution transmission electron microscopy. The core-shell configuration of nanofibers was verified by scanning electron microscopy and transmission electron microscopy images. The macroscopic ferromagnetic property of core-shell nanofibers was demonstrated by magnetic hysteresis loop. The local magnetoelectric (ME) coupling was confirmed by using dual frequency piezoresponse force microscopy (PFM) under an external magnetic field, showing magnetically induced evolution of piezoresponse and domain structure. The ferroelectric characteristics are demonstrated by the switching spectroscopy PFM. From PFM hysteresis and butterfly loops, it is observed that the piezoresponse amplitude is reduced while coercive voltage increased under external in-plane magnetic field, induced through the mechanical interactions between magnetostrictive CFO and piezoelectric BFO, from which the lateral ME coupling can be estimated quantitatively. The nanofibers thus can find a variety of applications as a one-dimensional multiferroic material
Fabrication of volcano-shaped nano-patterned sapphire substrates using colloidal self-assembly and wet chemical etching
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