Interferometer and method of calibrating the interferometer
US7511827B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 2006 |
| Grant date | Mar 31, 2009 |
| Priority date | — |
| Expiry date | Apr 27, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometer comprises a wavelength-variable light source. A reference light and a measurement light are synthesized, and the synthesized light is split into a plurality of split lights. A certain phase difference is provided between the split lights through phase shifting optical members. A plurality of interference fringe images formed by the phase-shifted split lights are captured at an imaging unit. Biases, amplitudes and the amounts of phase shift of the interference fringes formed by the plurality of split lights are calculated, based on interference fringe intensities of the imaged interference fringes, which are obtained by disposing a calibrating substrate instead of the measuring object varying the wavelength of the emitted light to plural values, and operating the imaging unit to capture a plurality of images of interference fringes obtained by the split lights.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.