Speaker
Description
We investigate a magnetized optical dielectric haloscope as a platform for high-frequency gravitational-wave detection. This approach is motivated by the close connection between proposed high-frequency gravitational-wave detectors and technologies originally developed for axion searches. Our setup consists of a multilayer silicon nitride and silicon oxide stack with optical focusing and single-photon readout, building on an optical haloscope setup currently in data-taking for axion searches targeting $m_a \sim 1\text{--}1.5\,\mathrm{eV}$. In its gravitational-wave configuration, the same setup is sensitive to frequencies of roughly $250\text{--}360\,\mathrm{THz}$. In this framework, the same externally applied magnetic field that mediates axion--photon conversion can also enable gravitational-wave-induced electromagnetic signal generation via the inverse Gertsenshtein effect. We emphasize that the gravitational-wave case is not a trivial extension of the axion one. In particular, we focus on the main differences between the two, including the possibility of conversion in vacuum, the phase and directional structure inherited from the incoming gravitational wave and the resulting implications for resonant, broadband and hybrid operating modes. We also present our approach to sensitivity estimation in the optical regime, taking into account the detector architecture, response and single-photon readout. Our study highlights the potential of dielectric haloscope technology as a cost-effective option for ultra-high-frequency gravitational-wave detection.
| Parallel session | New Physics Searches: Dark Matter and High-Frequency Gravitational Waves |
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