Optimization of DVD media parameters

DVD technology has established the importance of optimizing media for both the data signal and the tracking signal. The data signal from DVD-ROM is simply the integrated modulation on the quadrant photodetector, while the tracking signal is derived from the phase difference of the diagonal quadrant signals (differential phase detection or DPD). Closely related to the DPD signal is the quadrant pupil detection (QPD) signal, which is simply the difference of the diagonal quadrant signals. The QPD signal is a simple quantity to characterize, and it relates directly to the quality of the DPD signal. In this report, we show the dependence of the data signal modulation and the QPD amplitude on mark reflectivity, land reflectivity, and mark/land phase difference on reflection. Some interesting effects are observed, and these results should provide some guidance for media designers working on DVD-RAM.