Modelling axion generation and detection in optical microfibers

We present a novel experimental setup to generate and detect axions in the lab with a sensitivity over a broad axion mass range. Taking inspiration from nonlinear optical processes, this scheme utilizes laser-based four-wave mixing mediated by the hypothetical axion field. Two optical microfibers, each confining two lasers, run parallel to each other. Two lasers in the “generation fiber” interact to produce an axion field that “leaks” into the “detection fiber”, where it interacts with light and causes a detectable change in intensity. In this paper, we model the experimental setup using the axion-modified electromagnetic Lagrangian and the full equations for hybrid and transverse modes in cylindrical microfibers. Our analysis is centered around air-clad silica fibers with a diameter on the order of 1 μ m, and confining lasers with a wavelength near 1.55 μ m. We predict sensitivity for the axion-photon coupling constant, g αγγ , on the order of 10 − 6 GeV − 1 for an axion mass between 10 − 6 eV and 10 − 2 eV using experimental parameters realizable in the near future.