Homodyne interferometer and method of sensing material
US5900935A · kind A · utility
Inventors
Key dates
| Filing date | Dec 22, 1997 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Dec 22, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H9/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Faults, dimensions and other characteristics of a material or structure are sensed by a coherent beam's reflection from the material during ultrasonic or very fast vibration. The reflected beam acquires a phase substantially different from its original phase and from the phase of a reference beam split from the common source beam. The reflected beam and the reference beam are superimposed by diffraction in a multiple quantum well adaptive holographic beamsplitter, and the superimposed beams are detected by a photodetector capable of detecting small interference changes from ultrasonic surface displacements or perturbations. An apparatus and method defining an improved homodyne interferometer for performing the method is described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.