Optical information reproduction apparatus using homodyne phase diversity detection with improved SNR

摘要

In the optical information reproduction apparatus using Homodyne phase diversity detection, the S/N ratio of a reproduced signal is deteriorated due to the influence of a quantization noise generated in an A/D converter for digitalizing a differential signal. The optical information reproduction apparatus is arranged to have the A/D converter for digitalizing the differential signal having a vertical resolution equal to or higher than 9 bits.

主权项

1. An optical information reproduction apparatus using Homodyne phase diversity detection comprising:
a light source adapted to irradiate an optical information recording medium with light; a plurality of detectors adapted to detect a plurality of interference lights different from each other in a phase relationship between a signal light from the optical information recording medium and a reference light branched from the light source; a differential circuit adapted to generate a differential signal from the detectors; and an A/D converter having a vertical resolution of greater than or equal to 9 bits, and adapted to digitalize the differential signal, wherein the number of bits of the vertical resolution is determined based on a minimum modulation.