POLARIZERLESS MAGNETO-OPTIC SPEED AND TORQUE SENSOR.

摘要

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.