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US 5,493,220 AGranted
Magneto-optic Kerr effect stress sensing system
AssigneeNortheastern University
InventorsSteven A. Oliver, Charles A. DiMarzio, Stephen W. McKnight
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Abstract
A sensor system including a magnetooptic sensing element, a light source, at least one polarizer and at least one detector disposed about the sensing element. The sensing element has a first characteristic such that the sensing element provides a response to an applied external stress.
Claims19
A magneto-optic Kerr effect stress sensing system comprising:
- a light source;
- a magneto-optic Kerr effect stress sensor;
- a polarizer disposed between said light source and said magnetooptic Kerr effect stress sensor wherein said light source directs a light beam toward said polarizer and said polarizer passes light having a first predetermined polarization said such that the light having the first predetermined polarization is incident upon said magneto-optic Kerr effect stress sensor;
- a polarization splitter disposed to intercept light specularly reflected from said stress sensor wherein said polarization splitter passes at least a portion of the light incident thereon and reflects at least a portion of the light incident thereon wherein said polarization splitter is oriented to mix in a predetermined manner portions of the light signal having the first polarization with portions of the light signal having a second different polarization;
- a first detector disposed to receive the portion of the light signal which passes through said polarization splitter;
- and
- a second detector disposed to receive the portion of the light signal which is reflected by said polarization splitter.
4 more elements
A stress sensing system comprising:
- a light source;
- a magneto-optic Kerr effect stress sensor wherein said magnetooptic Kerr effect stress sensor comprises a magnetic film having first and second opposing surfaces and having a uniaxial anisotropy field characteristic of a predetermined intensity, wherein the magnetic film has at least one domain having a magnetization characteristic which rotates in response to application of an applied stress;
- a polarizer disposed between said light source and said magnetooptic Kerr effect stress sensor wherein said light source directs a light beam toward said polarizer and said polarizer passes light having a first predetermined polarization said such that the light having the predetermined polarization is incident upon said magnetooptic Kerr effect stress sensor;
- and
- a first detector disposed to receive the portion of the light signal reflected from said magneto-optic Kerr effect stress sensor.
2 more elements
Dependencies are inferred from the claim text.