Self-similarity of optical rotation trajectories around the Poincare sphere with application to an ultra-narrow atomic bandpass filter

James Keaveney; Dennis A. Rimmer; Ifan G. Hughes

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arXiv · 1807.04652

Self-similarity of optical rotation trajectories around the Poincare sphere with application to an ultra-narrow atomic bandpass filter

James Keaveney·Dennis A. Rimmer·Ifan G. Hughes

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Abstract

We present an investigation of magneto-optic rotation in both the Faraday and Voigt geometries. We show that more physical insight can be gained in a comparison of the Faraday and Voigt effects by visualising optical rotation trajectories on the Poincare sphere. This insight is applied to design and experimentally demonstrate an improved ultra-narrow optical bandpass filter based on combining optical rotation from two cascaded cells - one in the Faraday geometry and one in the Voigt geometry. Our optical filter has an equivalent noise bandwidth of 0.56 GHz, and a figure-of-merit value of 1.22(2) GHz$^{-1}$ which is higher than any previously demonstrated filter on the Rb D2 line.

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James Keaveney, Dennis A. Rimmer, Ifan G. Hughes. 2018-07-12. Self-similarity of optical rotation trajectories around the Poincare sphere with application to an ultra-narrow atomic bandpass filter. https://arxiv.org/abs/1807.04652

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