Grating-based optical probe
US5943128A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1998 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Jun 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dispersive grating, preferably in the form of a volume-phase holographic optical element, or HOE, is used as a beam combiner in an optical measurement probe of the type used to analyze induced radiative effects such as Raman or fluorescence detection. Although a reflective grating may be used, a transmission grating of holographic derivation is used in the preferred embodiment. Although the grating may define an area substantially equivalent to the cross-section or aperture of the collection path, a grating which consumes a fraction of the collection aperture may instead be utilized, thereby allowing collected light to pass around the grating to further enhance the efficiency of detection. As a further advantageous option, the grating may be fabricated with `power,` that is, with the capability of collimating excitation energy that has been focused onto the grating surface. In this manner, a "spot" grating may be positioned centrally along the axis of the collection path, thereby realizing the multiple advantages of relaxed alignment demand, reduced spurious scattering, and high efficiency and throughput.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.