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

Carr, Daniel Luke; Spong, Nicholas L.R.; Hughes, Ifan Glyndwr; Adams, Charles S

Abstract

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 short-term fluctuations in the laser power 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 / (λ2 - λ0 2) with coefficients A = 7.9 ± 0.2 × 107 deg T-1 m-1 nm2 and λ0 = 142 ± 13 nm.

Citation

Carr, D. L., Spong, N. L., Hughes, I. G., & Adams, C. S. (2020). Measuring the Faraday effect in olive oil using permanent magnets and Malus' law. European Journal of Physics, 41(2), Article 025301. https://doi.org/10.1088/1361-6404/ab50dd

• Journal Article Type: Article
• Acceptance Date: Oct 24, 2019
• Online Publication Date: Jan 13, 2020
• Publication Date: Jan 1, 2020
• Deposit Date: Oct 25, 2019
• Publicly Available Date: Jan 13, 2021
• Journal: European Journal of Physics
• Print ISSN: 0143-0807
• Electronic ISSN: 1361-6404
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 41
• Issue: 2
• Article Number: 025301
• DOI: https://doi.org/10.1088/1361-6404/ab50dd
• Public URL: https://durham-repository.worktribe.com/output/1286757