Directional waveguide coupler for ABS reflected light
US8238202B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2010 |
| Grant date | Aug 7, 2012 |
| Priority date | — |
| Expiry date | Dec 16, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A waveguide structure for a TAMR head is disclosed wherein at least one detection waveguide is formed parallel to a main waveguide and located a gap distance therefrom. A light source transmits light into the main waveguide and towards an ABS/medium interface. A plasmon generator converts light from the waveguide into plasmon waves that are directed onto a magnetic medium. Back reflected light is captured by the main waveguide, partially diverted into a detection waveguide, and transmitted to a photo detector that measures light intensity (IB) which correlates closely to the plasmon wave intensity at the ABS/medium interface. A controller linked to the photo detector is employed to calculate IB as a function of ABS/medium spacing in a non-write condition and this relationship can be used to control and maintain a constant plasmon wave intensity at the ABS during a series of TAMR write processes with a plurality of media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.