OPTICAL PICKUP

摘要

An optical pickup comprising a unitary combination of a light-emitting element and a light receiving element for signal receiving, wherein the noise due to the incidence of part of light from the light-emitting element onto the light-receiving element is reduced, while monitoring a part of the light from the light-emitting element. The depth h of a casing (2) of an optical integrated circuit (1) is reduced to cause stray light (10) of a beam (9a) from a laser diode (3), which is reflected from an inner surface (5a) of a transparent substrate (5), to fall between the laser diode (3) and a signal detecting photodiode (4), whereby the direct entry of the stray light (10) into the signal detecting photodiode (4) is prevented. A monitoring photodiode (14) is provided in a position where the stray light (10) fall, and the variation of the amount of light (9a) emitted from the laser diode (3) is detected in accordance with the change in the amount of the stray light (10).