Topical Review Recent progress in source development for extreme UV lithographyGerry O'Sullivan, Deirdre Kilbane & Rebekah D’Arcy855 Research Articles Two-mode superposition coherent states with spatial vortex structure for the quantized radiation fieldKaicheng Zhu, Shaoxin Li, Xiaojuan Zheng & Yiping Zhou873 Improved BER based on intensity noise alleviation using developed detection technique f..