Ultra-small microring resonator based on sub-micrometer fiber

The transfer function of the microring resonator is deduced,and the effects of the normalized loss,coupling coefficient and surrounding media on the resonance performance are investigated thoroughly.Utilizing the improved fused tapering tech-nique and ingenious self-coiling coupling method,a high-quality microring resonator(radius of about 500μm)with larger extinction ratio(>10 dB)and sharper resonance is designed and fabricated by a segment of continuous sub-micrometer fiber.The microring resonator constructed in this way demonstrates extremely small connection loss with communication fiber in contrast to the planar waveguide technology.     

A compact cascaded microring filter with two master rings and two slave rings for sensing application

In this paper,an ultra compact cascaded microring filter consisting of two master rings with radius of 2.5μm and two slave rings with radius of 1μm is presented and studied theoretically.The filter with a very large free spectral range（FSR）of 206 nm,a deep extinction ratio of 23 dB,a high quality factor of 2.76×105,and greatly suppressed spurious modes of less than 0.1 dB is achieved.The spectral responses of the filter are simulated by transfer matrix method,and the results show that this filter has a great potential of sensor application.     

An optic fiber sensor for multiple gases based on fiber loop ring-down spectroscopy and microring resonator arrays

A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtered signal from a broadband light source can be tuned with an absorption spectral line of gas. Therefore, through adding microring resonators horizontally and vertically, the number of target gases and filter range are increased. In this research, in the broad spectral range of about 0.9 μm, only the absorption spectral lines of target gases are filtered. The simulation results show that three target gases, CH₄, CO₂ and HF, can be simultaneously detected by the sensing system. Owing to the fiber loop ring-down spectroscopy, the whole system is optimized in mini-size and sensitivity, and we can choose different sensing methods to enhance the measurement accuracy for high and low concentration conditions.     

Optimal design and characteristics analysis of a polymer electro-optic switch with seven vertical-turning serial-cou- pled microrings

A novel 1 x2 polymer electro-optic （EO） switch based on seven vertical-mining serial-coupled microrings is proposed for dropping crosstalk and obtaining fiat boxlike spectrum. The device structure, theory and formulation are presented, and the microring resonance order and coupling gaps are optimized. The switching voltage of the device for obtaining crosstalk lower than -30 dB under through state is decided to be about 1.86 V. Under the operation voltages of 0 V （drop state） and 1.86 V （through state）, the switching performance is characterized, and the output spectrum is ana- lyzed. The calculation results show that the crosstalk at through state and that at drop state are -30.2 dB and -53.2 dB, respectively, while the insertion losses are 0.86 dB and 3.18 dB, respectively. Owning to the seven serial-coupled mi- crorings resonance structure, the proposed switch reveals the favorable boxlike spectrum compared with the simple device with only one microring, and thus the crosstalk under drop state is improved from -26.8 dB to -53.2 dB. Due to the low crosstalk, this device can be used in optical networks-on-chip for signal switching and routing.     

基于级联微环谐振器的集成化可重构光学上下路插分复用器

We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the microring resonators and can be modulated using the thermo-optic effect to achieve the reconfigurable functionality of the device. We demonstrate the reconfigurable add-drop multiplexing functionality for channel spacings of 100 GHz and 50 GHz, with the centre wavelengths of the channels aligned to International Telecommunication Union grid specifications. The crosstalk for channel spacings of 100 GHz and 50 GHz are less than..22:5 dB and..15:5 dB, respectively. The average tuning efficiency is about 4.5 mW/nm, and the response speed is about 13.0 kHz.     

Analysis of electro-optic switches with series-coupled multiple microring resonators

In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius of the m...     

Optimization of a polymer four-port microring optical router with three channel wavelengths

Optimization and simulation are performed for a polymer four-port microring optical router with three channel wavelengths, which contains four-group basic routing elements with two different ring radii. In terms of microring resonance theory, coupled mode theory and transfer matrix method, expressions of output power of basic routing element and optical router are derived. In order to realize single-mode propagation, low optical transmission loss and phase match between microring waveguide and channel waveguide, the device parameters are optimized. With the selected three channel wavelengths of 1550 nm, 1552 nm and 1554 nm, characteristics are calculated and analyzed, including output spectrum, insertion loss and crosstalk. Simulation results indicate that the device has 12 possible I/O routing paths, the insertion losses of three channel wavelengths along their routing paths are within the range of 0.02-0.61 dB, the maximum crosstalk between the on-port along each routing path and other off-ports is less than -39 dB, and the device footprint size is -0.13 mm^2. Based on the proposed structure, through proper selection on ring radius, the routing structure can also be used for other channel wavelengths. Therefore, the designed structure shows wide applications in integrated optical networks-on-chip （NoC）.     

Optimum design of a polymer electro-optic microring resonator switch

Novel transfer functions are presented for a polymer electro-optic microring resonator switches. The resonating process of the light in the microring is simulated using the formulas. Then the optimization of the structural parameters is performed, and the characteristics are analyzed, such as the resonance time, output spectrum, operation voltage, insertion loss and crosstalk were analyzed. The simulation results show that the designed device exhibits favorable switching functions.     

Fabrication of 17×17 polymer/Si arrayed waveguide grating with flat spectral response using steam-redissolution technique

Arrayed waveguide grating(AWG) is a key device in the wavelength-division multiplexing(WDM) system, and the flat spectral response of the AWG device is required.In this paper,the RIE process has been improved.By using the steam-redissolution technique,the insertion loss and the crosstalk have been reduced.Experimental results show that the central wavelength is 1550.86 nm,the channel spectral response flatness is about 1.5 dB,3-dB bandwidth is about 0.478 nm,insertion loss is 10.5 dB,and crosstalk is abo...     

16 channel 200 GHz arrayed waveguide grating based on Si nanowire waveguides

A 16 channel arrayed waveguide grating demultiplexer with 200 GHz channel spacing based on Si nanowire waveguides is designed.The transmission spectra response simulated by transmission function method shows that the device has channel spacing of 1.6 nm and crosstalk of 31 dB.The device is fabricated by 193 nm deep UV lithography in silicon-on-substrate.The demultiplexing characteristics are observed with crosstalk of 5-8 dB,central channel’s insertion loss of 2.2 dB,free spectral range of 24.7 nm and average channel spacing of 1.475 nm.The cause of the spectral distortion is analyzed specifically.     

近红外光谱技术在水果品质无损检测中应用的研究与现状

简单概述了我国水果产业的发展现状,着重阐述了国内外利用近红外光谱技术进行水果品质无损检测的最新研究进展,分析了当今研究中存在的问题,并对利用近红外光谱技术进行水果检测的前景进行了展望,提出了一些建议。     

星载差分吸收光谱仪转动部件测试系统设计

基于星载差分吸收光谱仪转动部件控制需求,设计了星载光谱仪转动部件的测试系统。采用微动开关复位加定步的电机运动方式实现电机的精确定位。采用脉冲调制（PWM）的方式实现驱动电流的精细调节。并搭建平台对系统进行重复性测试,实验结果表明,测试系统具有较高的可靠性和稳定性,能够满足光谱仪的精确定位要求,使电机在工作寿命内按计划完成定标工作。     

“计算机组成原理”设计性实践教学模式研究

本文阐述了"计算机组成原理"设计性实验教学的重要性,对设计性实验教学的目的和基本特征进行了归纳,对"计算机组成原理"设计性实验教学的现状进行了调查,对存在的问题进行了较深入的分析;在此基础上.对组成原理设计性实验的教学模式进行了研究,对设计性实验的体系进行了初步设计,并对"计算机组成原理"设计性实验的实施方法进行了探讨.     

杂质吸收对光子晶体滤波器设计的影响

为了研究杂质的吸收对光子晶体滤波器设计的影响,引入复折射率并利用特征矩阵法,计算了滤波透射峰的峰值和半峰全宽。滤波透射峰的峰值随杂质的消光系数增加而迅速减小,滤波通道透射峰的半峰全宽随消光系数增加而增大,滤波透射峰的峰值和半峰全宽都随吸收杂质的光学厚度的增加而减小。结果表明,设计光子晶体滤波器时,必须考虑杂质吸收这一重要因素,应选择消光系数小于0.002的掺杂材料,并且杂质的光学厚度应设计在2(λ0/4)左右。     

电子技术基础实验课程混合式教学设计

近年来,在线学习掀起了一场席卷全球的教育革命,MOOC/SPOC、翻转课堂、混合式教学对高等教育带来了前所未有的冲击。电子技术基础实验课程地位特殊,传统教学方式已无法满足创新性人才培养的需要,文章从其教学特点出发,提出了“线上教学+自主实验+翻转课堂”的混合式教学模式,同时还阐述了与此密切相关的集约化线上教学资源平台、智能化翻转教学环境以及多元化过程性考核评价机制三个重要环节。经研究发现,学生的课堂主动参与度、自主学习能力、创新思维能力、动手实践能力以及教师的教学创造力得到全面提升。教学环境支持课堂互动和全周期教学行为数据采集,体现了教学过程的信息化、教学实施的精准化和教学评价的客观化,实现了信息技术与实验教学的深度融合。     

非同相口径场瞬态辐射的计算

利用电磁脉冲的口径瞬态辐射场计算公式,针对圆形口径的线性相移、平方律相移等非同相口径场情况,计算了辐射高斯脉冲时的能量方向图、半能量波瓣宽度、面积利用系数等参数.计算表明,对于圆形口径非同相口径场,最大辐射场的方向为口径面法线方向,同时能量方向图关于口径面法线方向对称;随着口径的增大,波瓣变窄,无副瓣;随着平方律相移的滞后参数的增加,波瓣变宽,主瓣不分裂.     

Sn-Zn-Ag系无铅钎料焊接性能研究

讨论了电子软钎料的钎焊性能及其影响因素，并采用铺张面积法对Sn-Zn-Ag系钎料钎焊性能进行评估。钎料的钎焊性能很大程度上取决于钎料对基板的润湿性能，而润湿性能与液态钎料在基板上的液、固、气三相界面的界面张力有关。对润湿角(θ)与铺展面积(S)之间的关系进行了探讨。     

两种自适应杂波抑制技术的比较：AMTI及ADPCA技术性能的分析和比较

本文在讨论机载雷达地面杂波回波的基础上，分析了ＡＭＴＩ和ＡＤＰＣＡ系统的性能。对这两个系统从原理上，并利用计算机模拟结果及实验结果进行了比较。本文将有助于工程实现。     

浅析信息化时代下上市公司规模经济的发展

上市公司为了增强市场竞争力,不断扩大生产规模,追求规模经济,但是由于我国较低生产力水平、政府干预、体制等原因,上市公司的规模经济效果并不明显。同时,20世纪90年代以来,科学技术的日益发展,改变了企业发展的外部环境和条件,使得规模经济的实现方式发生了新的变化。在信息化时代下,规模经济理论需要进一步创新和拓展,企业按照新形势来选择合适的经济规模。     

凋亡神经元线粒体超微结构的形态计量学分析

目的:观察并分析人大脑皮层凋亡神经元线粒体超微结构的形态计量学变化.方法:取21例脑外科手术患者的额叶大脑皮质超薄切片中的正常神经元和凋亡神经元的电镜照片各80张,分为对照组与凋亡组.采用形态计量学方法对两组神经元的细胞体、细胞核、线粒体及细胞质基质灰度进行分析.结果:与正常神经元相比,凋亡神经元线粒体的体密度、面密度、数密度、比膜面明显增大(P＜0.01),比表面无明显改变(P＞0.05),线粒体基质与细胞质基质灰度之差明显增大(P＜0.01).结论:凋亡神经元线粒体未发生明显肿胀或增生,但其内膜和嵴的面积明显增加,基质密度降低.