Interferometer requiring no critical component alignment
US5116126A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1991 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Jan 7, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Michelson-type self-aligning interferometer utilizes a laser to produce an output beam of light that is split into signal and reference beams. The signal beam is directed through a Bragg-cell, for heterodyne detection, and a beam expander, for facilitating target acquisition, toward a retroreflector located on a target body. The signal beam is thereby reflected back through the beam expander and Bragg-cell toward the resonance mirror of the laser, and is now shifted in frequency by 2.OMEGA.. The returning signal beam remains co-linear with the output beam since it returns over the same path and through the same optical elements, especially the laser resonance mirror. Thus, the interferometer can accommodate a significant amount of component misalignment without loss of operation. The signal beam, once reflected from the resonance mirror of the laser and partially reflected by the beam splitter, is co-linear with the reference beam. The signal beam and reference beam are directed into a detector to produce an electrical signal. A frequency divider and a phase demodulator extract the phase of the electrical signal through heterodyne detection, the phase being proportional to the po…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.