What are the differences between cyanine, phthalocyanine and azo dyes?
There are a number of important recording characteristics and longevity issues associated with each dye and reflectivity coating combination. Each media manufacturer strives to balance the engineering characteristics of the dye to insure greater compatibility with recorders and readers and long archive life. In addition to cyanine and phthalocyanine, there is also azo dye. Cyanine dye and its metal-stabilized derivatives were originally used because the “Orange Book, Part II” referred to the recording characteristics of cyanine-based dyes in establishing CD-Recordable standards. Consequently, dyes based on cyanine tend to have a wide range of acceptable recording power levels and recording speeds. “Phthalocyanine” dye is a much more stable dye that is more tolerant when exposed to light, heat and humidity, which improving after recording longevity and reliability. Azo dye has been used in other optical recording media and is now being used in CD-R. These different dyes, in combination
