  Axion-like particles are a broad class of dark matter candidates which are
expected to behave as a coherent, classical field with a weak coupling to
photons. Research into the detectability of these particles with laser
interferometers has recently revealed a number of promising experimental
designs. Inspired by these ideas, we propose the Axion Detection with
Birefringent Cavities (ADBC) experiment, a new axion interferometry concept
using a cavity that exhibits birefringence between its two, linearly polarized
laser eigenmodes. This experimental concept overcomes several limitations of
the designs currently in the literature, and can be practically realized in the
form of a simple bowtie cavity with tunable mirror angles. Our design thereby
increases the sensitivity to the axion-photon coupling over a wide range of
axion masses.
