Polarizerless magneto-optic speed and torque sensor
US5192862A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1991 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Dec 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/0322
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A polarizerless optic sensor is provided that uses a random domain magneto-optic film and a modulated normal magnetic field to vary or modulate the energy distribution in a diffraction pattern. Light is transmitted through the film and is diffracted according to a domain duty cycle so that the center beam intensity is a function of the Faraday rotation angle of the material and the intensity of the applied normal magnetic field. The polarizerless sensor can be used to realize a speed and torque sensor, an optical switch, a magnetic field sensor and many other types of devices. The invention can be used with polarized and unpolarized input light. The sensor can be implemented using a random domain film or a stripe domain film to create a phase grating diffraction pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.