AN OPTICAL DRIVE CAPABLE OF REPLAYING OPTICAL CARRIERS WITH HIGH BIREFRINGENCE

摘要

The invention relates to an optical drive for reading information from an optical disk (1) with a high birefringence. A radiation beam (5) has a modulated read power level of frequency F1. A polarizing beam splitter (PBS; 6) guides the reflected beam (8) from the disk (1) towards a photo detector (10) that outputs optical response signals (RS). The optical response signals (RS) are converted to optical response parameters (RP) that are compared with a pre-determined optical response parameter reference values (RP_ref). If a sufficient deviation (?) is present it is indicative of an optical feedback from the beam splitting means (PBS; 6) towards to the radiation source (4). The processing means (52) can then change the first modulator frequency (F1) of the radiation beam (5) to a second modulator frequency (F2) so as to decrease the optical feedback. The invention provides a relatively simple yet effective way of compensating for a high birefringence value on an optical carrier wherefrom information is replayed.