(Cambridge)SPIE-The International Society for Optical Engineeringv.518 (Cambridge)SPIE-the international society for optical engineering (Cambridge)SPIE-the international society for Optical engineering (San Diego)SPIE-the international society for optical engineering;V.507 (Cambridge)SPIE-The International Society for Optical Engineering (San Diego)SPIE-the international society for optical engineering (Orlando)SPIE-the international society for optical engineering (California)SPIE-the international society for optical engineering SPIE-the international society for optical engineering;V.517 (San Diego)SPIE-the International Society for Optical Engineering