Proposal for a Search for Cosmic Axions Using an Optical Cavity

A high finesse optical cavity can be used to search for cosmic axions in the mass range ${10}^{-6}<m_a<{10}^{-4}\mathrm{eV}$. Either a two-arm or a single-arm cavity is suitable, and in either case the signal appears as resonant sidebands imposed on the carrier. Assuming for the local axion density the usual figure of ${\rho }_a=500\mathrm{Mev}/{\mathrm{cm}}^3$, the KSVZ axion line $g_{a\gamma \gamma }/m_a=0.4{\mathrm{GeV}}^{-2}$, can be reached over the full mass range in a 1 yr search.

Figure 1

Proposed layout of the coupled cavities.