| 摘要 |
PURPOSE:To form an optical reproducing pickup on a light-weight slider and to enable the pickup to make high-speed access and, at the same time, to improve the S/N of the pickup by leading the outgoing light from a recording medium through a branched optical waveguide and detecting the light through a 1st and a 2nd mode filters having desired slopes, and then, performing a differential process on the detecting outputs of the filters. CONSTITUTION:The light of a laser diode 18 is made incident on a recording medium 11 through an optical waveguide 21A provided with a polarizer and the outgoing light from the medium 11 is led to branched optical waveguides 21B, 21B1, and 21B2 and made incident on 1st and 2nd detectors 19 and 20 through the 1st and 2nd mode filters 24 and 25 respectively having prescribed slopes against the plane of polarization of the light made incident on the medium 11. Outputs of the detectors are processed at a differential amplifier 35, by which a synchronizing component is removed, and high-S/N reproduced signals having a doubled signal component are outputted. When such a constitution is used, no large-sized optical system is required for the object lens system and the active layer of the diode 18 can be made parallel with the surface of a substrate, since it becomes unnecessary to tilt the mode filters which become light trans-mitters. Therefore, this optical pickup can be formed on a light-weight slider and high-speed access can be performed with the pickup. At the same time, the S/N can be improved. |
