Abstract: New and useful methods and systems for reading optical discs, such as multi-layer Blu-ray discs are disclosed. For example, in an embodiment a device for reading two-layered optical discs includes a laser diode capable of emitting light, a set of optics including a fixed collimator, the set of optics providing a numerical aperture (NA) of substantially less than 0.85, and a detector for detecting laser light focused on a two-layer optical disc to produce a stream of detected bits.

Abstract: New and useful methods and systems for reading optical discs, such as multi-layer Blu-ray discs are disclosed. For example, in an embodiment a device for reading two-layered optical discs includes a laser diode capable of emitting light, a set of optics including a fixed collimator, the set of optics providing a numerical aperture (NA) of substantially less than 0.85, and a detector for detecting laser light focused on a two-layer optical disc to produce a stream of detected bits.

Abstract: A system includes an encoding module and a laser driver module. The encoding module is configured to encode a data stream. The laser driver module is configured to convert the encoded data stream into a write signal including one or more edges. The write signal is output to an optical writer. The laser driver module is configured to adjust an actual position at which the optical writer writes a first edge of the one or more edges on an optical storage medium away from a desired position for the first edge. The adjustment is made based on (i) a first preceding edge position, (ii) a first following edge position, (iii) a second preceding edge position or a second following edge position, and (iv) a third preceding edge position or a third following edge position. The first edge corresponds to a beginning of a mark edge of the write signal.