Magneto Optic Kerr Effect (MOKE) experiments are designed to detect small changes in polarization that occur because magnetic fields influence the polarization state of optical radiation as it passes through a transparent medium.
PEM Setting: quarter-wave retardation (λ/4)
Polarization Modulation: right and left circular polarized light
Lock-in reference: PEM's 1st Harmonic
The modulated light is reflected by the sample, which is situated in the center of the electromagnet poles. Setting the analyzer angle to 0° greatly simplifies the mathematical relationship between the intensity ratios measured and the magneto-optical parameters. The following equation represents the resulting signal intensity. From the lock-in values the MOKE parameters θk and εk may be calculated.
V1f and V2f are the voltages of the first harmonic signals from the lock-in
VDC is the DC signal
J1 and J2 are Bessel function coefficients
The derivation of these equations may be found in the Magneto-Optic Kerr Effect Application Note.
- Data Storage
- Disk Recording Systems
- Dynamic Studies of Film Growth
TYPICAL HEAD ASSEMBLIES
HINDS PRODUCT SOLUTIONS
R. Atkinson, G. Didrichsen, W.R. Hendren, I.W. Salter and R.J. Pollard, "Dynamic in situ optical and magneto-optical monitoring of the growth of Co/Au multilayers", Phys.Rev. B, 62, 18, 12 294-12 302 (2000).
R. Atkinson, G. Didrichsen, W.R. Hendren, I.W. Salter and R.J. Pollard, "Dynamic in situ optical and magneto-optical monitoring of the growth of Co-Pd multilayers" J. Phys.: Condens. Matter. 13, 691-705 (2001).
Contact us for additional information about using PEMs in a Magneto-Optic set-up.