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Magnetic Light Modulator

IP.com Disclosure Number: IPCOM000095377D
Original Publication Date: 1965-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Argyle, BE: AUTHOR [+3]

Abstract

The europium chalcogenides EuO, EuS, EuSe and EuTe can be employed to modulate or switch light beams under the influence of applied magnetic fields. Each europium chalcogenide normally is capable of absorbing light waves whose frequencies lie within a predetermined absorption band. Under the influence of a magnetic field the edges of this absorption band are shifted. Hence light having a frequency near the edge of the normal absorption band, and within the range of variation afforded by the applied magnetic field can be selectively absorbed or transmitted according to the variations of the applied field.

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Magnetic Light Modulator

The europium chalcogenides EuO, EuS, EuSe and EuTe can be employed to modulate or switch light beams under the influence of applied magnetic fields. Each europium chalcogenide normally is capable of absorbing light waves whose frequencies lie within a predetermined absorption band. Under the influence of a magnetic field the edges of this absorption band are shifted. Hence light having a frequency near the edge of the normal absorption band, and within the range of variation afforded by the applied magnetic field can be selectively absorbed or transmitted according to the variations of the applied field.

This property enables employment of the europium chalcogenides as magnetically controlled light modulators or light switches. Such control the transmission of monochromatic light within selected portions of the optical spectrum. Since the various chalcogenides have different absorption bands and are capable of forming a system of solid solutions with one another a continuous series of materials is available for intensity modulation of monochromatic light beams. This is in the wavelength range from 6,500 Angstroms to 12,000 Angstroms. Ambient temperatures are kept below the lowest temperature at which ferromagnetism can exist in such a material.

The device provides an exceptionally accurate and sensitive magneto-optic modulation of monochromatic light beams. It is superior to magneto-optic modulators which use the Faraday rotational effect...