Measuring Magnetic Field with Light Presentation of Thesis

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 light in polarizer modulating birefringent crystal polarizer detector

The MOSS

Interferogram for the p-component for the two s-components

Switching between the linear components Contrast modulation

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

Switching between the circular components Phase modulation Contrast modulation

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

Stokes Vectors Sp=. 5 (sin 2 g cos 2 b, sin 2 g sin 2 b, 0) Ss+=. 25 (-sin 2 g cos 2 b, -sin 2 g sin 2 b, -2 cos g) Ss-=. 25 (-sin 2 g cos 2 b, -sin 2 g sin 2 b, 2 cos g)

The Zeeman Spectrometer

Raw Signal for Linear Polarization field off field on

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

Magnet close up

The real thing

All the stuff

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

Spectrometer B vs Hall probe B 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 0 0. 02 0. 04 0. 06 0. 08 0. 12 0. 14 0. 16 0. 18 0. 2

Constant tilt angle as B increases 150 100 50 0 -50 -100 -150 0 0. 02 0. 04 0. 06 0. 08 0. 12 0. 14 0. 16 0. 18 0. 2

Measurement of tilt angle 200 150 100 50 0 -150 -100 -150 -200 0 20 40 60 80 100 120 140 160 180