Angular tuning of defect modes spectra for one dimensional photonic crystal filters with a liquid crystal layer

A tunable photonic crystal filter with a twisted nematic liquid crystal layer is proposed. The defect modes spectra with varying incident angles are discussed in detail by 4×4 matrix method. The results show that the defect modes are mainly decided by the applied voltage when the incident angle is smaller than 8°. As the incident angle further increases, the band gap and the defect modes shift toward the shorter wavelength side, and the changes of the two modes are different. In the lower voltage range, the defect modes can be tuned not only by the applied voltage but also by the incident angle. In the higher voltage range, the defect modes can be further tuned by varying incident angle and the different modes can be separated from each other by a big incident angle.     

谈“数字印后增效+防伪技术元素”为包装赋能 成为新一代的包装防伪技术

<正>在目前激烈的市场竞争下,商家在产品包装上不断升级改版,煞费苦心,使得产品包装各色各异,美不胜收。对于一些企业商家而言,产品包装的外在因素必不可少,但保护品牌的意识不容忽视和放松。在此市场需求下,就需将多种防伪技术运用到产品包装上,形     

平行向列相液晶法-珀滤光片的光学特性分析

采用一种简单、稳定的方法-差分迭代法对平行向列相液晶在外电场作用下指向矢的空间分布进行了模拟计算.在此基础上,利用琼斯矩阵方法对平行向列相液晶法布里-珀罗滤光片的本征偏振态及光学特性进行了研究.结果表明,平行向列相液晶法布里-珀罗滤光片的共振模式是两组互相垂直的线性偏振态,且具有调谐范围宽,偏振敏感等特点.     

改造分切机存在的问题保证特种标签材料分切质量

<正>目前笔者公司的分切机已经不能满足现在特种标签材料的分切要求,主要存在以下问题:张力控制不稳,对膜类产品识别跟踪不好,分切膜类产品时产生静电击穿芯片,分切膜类产品使用圆刀分切效果不好,芯片有压碎的现象,无法保证分切质量。针对以上问题,公司发挥工程技术人员的力量,自主对分切机进行了机械设计,革新改造成功,保证了产品质量。     

Dependence of transmission spectra on director orientation in the photonic crystal with a liquid crystal layer

The transmission spectra of one-dimensional(1D) photonic crystals(PCs) with parallel and twisted nematic liquid crystals(LCs) as defect layers are discussed by 4 × 4 matrix method,respectively.The results show that the photonic band gap(PBG) mainly depends on the periodic arrays of dielectric composites.The orientation of director and the symmetry of the director configuration have important influence on the location and amplitude of defect modes.The location and amplitude of defect modes can be controlled conveniently by changing the orientation of director.The symmetry of the director configuration can help us understand the defect modes spectra.     

轴对称型BGO反康屏蔽探测器研制

着重报告了自行研制的轴向对称型BGO反康屏蔽探测器的基本结构、抑制原理及其抑制性能的测试结果。测得^60Coγ射线源的康普顿抑制系数在能区100—300、300—800、800—1100keV范围内分别为2．3、4．1和4．6,且峰总比为37％(对相对效率为30％的HPGe探测器)。     

RFID应用于血液全流程追溯管理

在"互联网+"应用浪潮中,血液供保中心(以下简称血站)积极利用互联网、物联网技术来提升管理的信息化和自动化水平. RFID作为非接触式自动识别技术,其优点在于可以无接触的方式实现远距离、多标签甚至在快速移动的状态下进行自动识别.而计算机网络技术的发展,尤其是互联网技术的发展使得全球信息传递的即时性得到了基本保证.在此基...