Measuring Magnetic Field with Light Presentation of Thesis for the Masters of Science Degree by Andreas Danielsson

The Zeeman Effect  Field off  No splitting  Field on   Zeeman triplet

The Zeeman Triplet and Its Polarization

Information Carrier Orientation of B encoded in the polarization Magnitude of B encoded in the frequency separation  Polarimeter to analyze the polarization states Interferometer to analyze the frequency information

MOSS-signal polarizer modulating birefringent crystal polarizer detector light in

The MOSS

Interferogram for the  component for the two  components

Switching between the linear components Contrast modulation

Interferogram for the two  –components separately Solid line -lower frequency Dashed line -higher frequency

Switching between the circular components Phase modulation Contrast modulation

I = I 0 /2(1+s. p) s = (s 1, s 2, s 3 ) p = (cos    sin    sin  1, sin  2 cos  1 ) Select s 1, s 2 or s 3 by appropriate choice of p. Polarimeter

Stokes Vectors S  =.5 (sin 2  cos 2  sin 2  sin 2  ) S  =.25 (-sin 2  cos 2  -sin 2  sin 2  -2  cos  ) S  =.25 (-sin 2  cos 2  -sin 2  sin 2  cos  )

The Zeeman Spectrometer

Raw Signal for Linear Polarization field off field on

Raw Signal for Circular Polarization  = 75 o field on  = 105 o field on

Magnet close up

The real thing

All the stuff

Demodulation Algorithm (8f) f Frequency spectra MOSS carrier Polarimeter sidebands Demodulation routine in LabView gives field strength and angles in real time.

Spectrometer B vs Hall probe B            

Constant tilt angle as B increases         

Measurement of tilt angle          