Measurement apparatus and measurement method
US11885879B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 2020 |
| Grant date | Jan 30, 2024 |
| Priority date | — |
| Expiry date | Nov 17, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/4917
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A measurement apparatus includes a laser apparatus, a branch that branches a frequency-modulated laser beam into a reference light and a measurement light, a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is the measurement light radiated onto an object to be measured, a first analyzer that analyses a first signal component corresponding to a difference in a propagation distance between the reference light and the measurement light on the basis of the beat signal, a second analyzer that analyses a second signal component corresponding to a cavity frequency of an optical cavity on the basis of the beat signal, and calculation circuitry that calculates the difference in the propagation distance between the reference light and the measurement light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.