| 摘要 |
A magneto-optical device which is responsive to magnetic fields by means of a Tyndall Effect in a particular direction exhibited by aligned magnetic colloidal particles suspended in an illuminated liquid medium. The liquid medium is contained in a transparent vessel and has magnetic particles in a very low density, such that the liquid is substantially transparent to the naked eye. A light source is positioned to illuminate the liquid medium and a light-sensing device or photocell is positioned to receive light scattered by the magnetic particles. The light-sensing device is positioned at a predetermined angle from the paraxial direction of the light source. All colloidal solutions, when illuminated by a beam of light, exhibit the Tyndall Effect, i.e. a visible scattering of light by the colloidal particles. When the magnetic colloidal solution of this device is brought into the presence of a magnetic field, the magnetic particles become aligned, causing the directed scattering of light called herein the Directional Tyndall Effect, which scattering can be detected by the photocell. In order to minimize the effects of surrounding light, the vessel containing the liquid medium can be enclosed in an opaque container with the photocell and light source mounted in appropriate apertures. For use in varying applications, two photocells can be provided, with the photocells and light source in an orthogonal arrangement.
|
