OPTICAL PICK-UP, OPTICAL INFORMATION RECORDING AND PLAYBACK DEVICE, COMPUTER DEVICE, AND OPTICAL DISC RECORDER

摘要

Disclosed is a an optical pick-up which can stably detect with high accuracy the relative angle of inclination between the end face of a solid immersion lens (SIL) and the surface of an optical recording medium. Also disclosed are an optical information recording and playback device, a computer device, and an optical disc recorder. The centre of a first beam and the centre of a second beam are at different locations on the end face of an SIL (108b). A beam splitter (106) is disposed between a beam expander (105) and an objective lens optical system (108). A photodetector (121) comprises a first light reception region which receives light from the first convergent beam, and a second light reception region which receives light from the second convergent beam, and the relative angle of inclination between the tip surface of the SIL (108b) and the surface of an optical disk (200) is detected on the basis of the difference between the amount of light received in the first light reception region and the second light reception region.