基于压缩感知及光学理论的图像信息加密

针对信息加密系统中信息安全性不理想的问题,提出一种基于压缩感知的光学图像信息加密方法.在发送端,自然图像经稀疏表示、随机投影实现图像信息加密;然后将降维后的观测值通过4F双随机相位编码光学系统进行二次加密并将其融入宿主图像,实现信息加密及隐藏.在接收端,图像信息经双随机相位编码技术解码,通过正交匹配追踪算法实现原始图像信息重构.该系统能有效降低数据传输量、减小随机相位板大小.且收发方只需按照规则生成密钥而不需传输密钥,保证了密钥的安全性.仿真结果表明:解密恢复图像质量理想,峰值信噪比为30.899 1dB,且系统能较好地抵抗裁剪、噪音污染、高通滤波、旋转等攻击,鲁棒性强,安全性高.     

Optimum design of photoresist thickness for 90-nm critical dimension based on ArF laser lithography

In this work,a 90-nm critical dimension(CD) technological process in an ArF laser lithography system is simulated,and the swing curves of the CD linewidth changing with photoresist thickness are obtained in the absence and presence of bottom antireflection coating(BARC).By analysing the simulation result,it can be found that in the absence of BARC the CD swing curve effect is much bigger than that in the presence of BARC.So,the BARC should be needed for the 90-nm CD manufacture.The optimum resist thickness for 90-nm CD in the presence of BARC is obtained,and the optimizing process in this work can be used for reference in practice.