Low bias drift modulator with buffer layer
US7324257B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2005 |
| Grant date | Jan 29, 2008 |
| Priority date | — |
| Expiry date | Mar 16, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/21
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to an electro-optic modulator structure containing an additional set of bias electrodes buried within the device for applying bias to set the operating point. Thus the RF electrodes used to modulate incoming optical signals can be operated with zero DC bias, reducing electrode corrosion by galvanic and other effects that can be present in non-hermetic packages. The buried bias electrodes are also advantageous in controlling charge build-up with consequent improvement in drift characteristics. The bias electrode material is useful for routing bias signals inside the device, in particular to external terminals, as well as forming encapsulating layers to permit operation in non-hermetic environments, thereby lowering manufacturing costs. Embodiments using both X-cut and Z-cut lithium niobate (LiNbO3) are presented. For the latter, the bias electrodes can be split along their axis to avoid optical losses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.