Optical head assembly with efficient light source coupling surface and method of construction
US4779259A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1986 |
| Grant date | Oct 18, 1988 |
| Priority date | — |
| Expiry date | Apr 23, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical IC-type head assembly for recording and for reading information on an optical disc, comprising a substrate, a light guiding layer comprising a dielectric thin film formed monolithically on the substrate, a laser oscillator for injecting the laser beam into the light guiding layer, a grating coupler for converging the laser beam on the optical disc, and a photo detector for receiving the beam reflected by the optical disc and coming out of the grating coupler. In one embodiment the substrate is made of material having cleavability. One side surface of the light guiding layer receiving the laser beam is a break surface formed by cleaving the substrate along the cleavage plane. The photo detector is disposed at the break surface of the light guiding layer. The substrate is preferably made of single crystal material. In another embodiment, a beam splitter is disposed between the laser oscillator and the grating coupler for splitting the reflected beam coming out of the grating coupler into two symmetrical beams. Each split beam forms an acute angle with respect to the optical axis of the reflected beam. The acute angle is preferably less than 30 degrees. The beam splitter ma…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.