Measurement and modeling of optical disk noise

This paper discusses the various components of the noise in the readback signal from an optical disk and suggests methods for measuring them. An analysis is presented of the relationship between optical efficiency of an M-O head, light intensity at the detector(s), choice between PIN and avalanche photodetectors and the resulting noise levels. A number of measured noise spectra from grooved and ungrooved substrates and disks are presented and mathematical models are used to explain the results. In particular a simple model of an M-O system with differential detectors is included.