Axion Polarimeteric Experiment (APE)

The interaction of axions and axion-like particles with photons would induce a time-varying rotation of the polarization of linearly polarized laser light. This paper presents a highly sensitive setup for detecting the polarization rotation using a polarimetric setup with two quarter-wave plates inside a Fabry-Pérot cavity. This configuration allows exploration of a previously untested region in the parameter space, covering coupling constants in the range of $(5\cdot 10^{-13}$ - $10^{-11})~\text{GeV}^{-1}$ and axion masses from ($10^{-16}$-$10^{-12})~\text{eV}$.