Coupling-enhanced surface etched gratings
US7609919B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2007 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Sep 12, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention describes the method and apparatus for enhancement of coupling efficiency in effective-ridge laterally-coupled surface-etched grating waveguide structures, where a slab waveguide has a sequence of the periodic parallel segmented trenches etched from its top surface, such that the segments of intact material having higher refractive index than that in the surrounding segments of periodic trenches form the effective ridges which confine the optical field in and around these ridges, on one hand, and provide bidirectional coupling for the confined modes experiencing Bragg reflection from the segments of the periodic trenches, on the other. The invention discloses the designs of the multiple effective ridge laterally coupled surface-etched grating waveguide structures, which enhances the coupling efficiency as compared to a conventional single effective ridge grating design because of an intended dilution of the lateral confinement caused by the multiple effective ridges, resulting in an increase of the optical mode's overlap with the surface etched grating formed everywhere outside the effective ridges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.