Technology for Polarization Measurement

Use of PEMs in Magneto Optic Kerr Effect Experiments

October 13th, 2011

Do you need to measure magneto-optic effects? Are you working with magnetic thin film storage materials?

Hinds Instruments provides two solutions: a component-based build-it-yourself package and a full turnkey system. Both of these are based on Hinds’ Instruments Photoelastic Modulator (PEM) technology.

Hinds PEMs provide increased sensitivity for MOKE measurements. In addition, Hinds Signaloc lock-in amplifiers (LIAs) and photodiode detectors (DETs) are optimized for use with PEMs. This allows sensitive measurements of thin magnetic films using reflection or transmission techniques. “The beauty of the photoelastic modulation technique is that, not only does this increase signal-to-noise ratio for the detection of very small magneto-optical effects and can, in some instances, eliminate defects in polarizing devices but the detection of both fundamental and second harmonic signals that are generated are directly proportional to the Kerr (or Faraday) ellipticity and rotation, respectively. This means that these two extremely important parameters can be measured simultaneously”, according to Prof. Ron Atkinson (The Queen’s University Belfast, Professor Emeritus, Hinds Newsletter, Fall 2001). The Queen’s group reported precision typically of the order of 1 arc sec for Kerr rotation values and have, in the past, been able to detect MO signals from films that are the thickness of a single atom.

Hinds component-based packages contain a magnetic field compatible PEM, a light source, one or two lock-in amplifiers, a photodiode detector, and two polarizers.  Mounts and other optical components needed for bench set-up can be provided by Hinds as well.

When Hinds Instruments develops turnkey solutions, such as the MOKE system, the finished product is an all inclusive, user-friendly tool. Standard magnetic field densities are available from 500 Gauss to 1 Tesla. Systems with other field densities can be custom designed.

Hinds Instruments, Inc. is the world leader in developing and supplying polarization modulation technology for a broad range of applications. With 40+ years of polarization modulation experience, Hinds Instruments PEM-based solutions are proven tools for laboratory and research applications. Hinds’ family of products includes modulators, Stokes polarimeters, Mueller matrix polarimeters, MOKE measurement systems and Exicor ® birefringence measurement systems. For more information, please contact Hinds Instruments.

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