Optical pickup device with substantially mutually orthogonal reflection surfaces
US5835472A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1993 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | May 17, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An integrated optical pickup device for a magnetooptical recording medium (e.g. a magnetooptical recording disk) and/or an optical recording medium (e.g. an optical recording disk) in which a plurality of focusing grating couplers are formed on an optical waveguide layer manufactured on a substrate. A light reflected from a magnetooptical disk or an optical disk is guided by the focusing grating couplers into the waveguide layer to be separated and to be converged therethtough. The converged lights are detected so as to produce a tracking error signal, a focusing error signal, and an information readout signal. The plural focusing grating couplers are fabricated at an identical location on the waveguide in a superimposed fashion. This increases the utilization efficiency of reflection light per each unitary area of the focusing grating couplers and hence the signals are obtained in a stable state. Between a semiconductor laser and a collimation lens, there is formed a composite beam splitter having two reflection surfaces. Reflection lights from the magnetooptical disk are respectively reflected by these reflection surfaces and are then received by photosensors. Analyzers are dispo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.