Optischer Abtaster, der eine Vertical Cavity - oberflächenstrahlende Laserdiode verwendet

摘要

An optical pickup using a vertical cavity surface-emitting laser diode as a light source in place of a conventional edge-emitting laser diode. The pickup comprises an intergrated vertical cavity surface-emitting laser diode structure for use as both a light source 11 and a photodetector 10. Both elements can be produced in one batch process thereby providing a productivity improvement and a cost reduction. When used as a light source, light generated from the vertical cavity surface-emitting laser diode exhibits better properties than that generated from an edge-emitting laser diode. Also, the circular light beam from the vertical cavity surface-emitting laser diode has much less astigmatism than the elliptical light beam generated from the edge-emitting laser diode, thereby providing a low rate of optical loss in an optical system. A hologram element 3 diffracts the light generated by the laser diode 11 and an objective lens 2 focuses the light onto the disc 1. <IMAGE>