AudioDev has introduced its Rite CD-R writer, which it says monitors and optimizes optical density (combination of dye layer thickness and texture) in the CD-R manufacturing process. With the help of CATS Rite CD-R, manufactured CD-R discs can be written at different laser powers and different speeds, currently up to 24x.
The written discs are then tested using the CATS SA3 Advanced CD-R analyzer. Test results can be compared to establish the process window and identify for example the optimal dye thickness for a particular type of dye.
According to AudioDev, the Rite CD-R is useful because small variations in the optical density, which is the combination of the dye layer thickness and the texture of the dye, can affect Optimum Recording Power (ORP) and the writing strategies required. Small variations in dye layer thickness affect mainly the absorbed power, but depending on the dye technology, it can also affect parameters like jitter and BLER. Some writers have a "read-after-write" function, which is used to adjust the writing power when the dye layer thickness varies.
However, depending on the dye technology, the process is more or less sensitive when the dye layer thickness is not optimal. The writer can not generate as good results as when the thickness and optical density are optimal, no matter what writing power or writing strategy used. The mixture of solvents in the dye (during the dye-coating process) affects the hardening of the dye and can generate flow patterns, which affect the readability of the written disc.
Using a CD-R writer that can write fixed power steps will clearly and rapidly show if the optical density is optimized or not, notes AudioDev. The correct optical density does not only generate the best result after recording, it also gives a greater writing-power margin for the recorders, the company concludes.