Verfahren und Vorrichtung zum Lesen optischer Speichermedien
The method involves using the polarised light from a laser diode , which is directed through a collimator lens  and an optical deflector  to produce a static emission  and an oscillating emission . Both of the emissions pass through a polarising decoupling unit, and onto a mirror for deflection at right angles through a quarter wave plate  and focal lens  positioned above the disc . The static beam is modulated by the oscillating beam responding to information for the tracks [1a,1b,1c]. Preferably the oscillation frequency is at least 1 MHz. USE - For compact discs ADVANTAGE - Provides increased data transfer rate.
DE 1996-19636595 A: 19960910