MEMS tunable optical filter system with moisture getter for frequency stability
US6776538B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2001 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Jan 9, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/4285
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In optoelectronic systems, package moisture can affect stress levels in dielectric coatings on MEMS devices. Specifically, as the moisture content in these dielectric coatings changes, there are concomitant changes in the material stress. These changes in material stress can affect the operation of the overall MEMS device. Specifically, in the context of tunable filters, moisture can lead to a drift in the size of the optical resonant cavity over time as changes in material stress affect the MEMS structures. According to the invention, a getter is added to the package to absorb moisture, and thereby stabilize the operation of the optical filter, and specifically prevent uncontrolled drift in the size of its optical cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.