Cavity enhanced optical spectroscopy with a cavity having a predetermined deviation from a mode degeneracy condition
US7535573B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2007 |
| Grant date | May 19, 2009 |
| Priority date | — |
| Expiry date | May 11, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/39
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Improved ease of mode matching to a passive optical cavity is provided by selecting a cavity design that has a predetermined deviation from a reference cavity design having high transverse mode degeneracy. This predetermined deviation tends to be small, so that the first overlap of high-order transverse modes with the lowest order transverse mode in frequency occurs at relatively high transverse mode numbers. Coupling to high-order transverse modes is thereby reduced, since high-order transverse modes having relatively high transverse mode numbers tend to be more difficult to couple to, and tend to have high loss. During assembly of such a cavity, it can be useful to apply a perturbation to the cavity to further optimize mode matching. For example, the length of an enclosed cavity can be adjusted by altering the number and/or length of spacers in the cavity housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.