Measuring the Faraday effect in olive oil using permanent magnets and Malus' law [dataset]

We present a simple permanent magnet set-up that can be used to measure the Faraday effect in gases, liquids and solids. By fitting the transmission curve as a function of polarizer angle (Malus’ law) we average over fluctuations in the laser intensity and can extract phase shifts as small as ± 50 µrads. We have focused on measuring the Faraday effect in olive oil and find a Verdet coefficient of V = 192 ± 1 deg T−1 m−1 at approximately 20 ◦C for a wavelength of 659.2 nm. We show that the Verdet coefficient can be fit with a Drude-like dispersion law A/(λ 2 − λ 2 0 ) with coefficients A = 7.9 ± 0.2 × 107 deg T−1 m−1 nm2 and λ0 = 142 ± 13 nm.