Speaker
Description
Classical imaging systems are limited by the size of their primary aperture and the wavelength of light being observed [1]. This diffraction limit reduces our capacity to make astronomical observations. Interferometry allows us to increase the size of our primary aperture through aperture synthesis, drastically improving our resolving capacity. The largest existing optical interferometer has a maximum baseline of 331m [2]. Building a longer baseline interferometer would require using fibre optic cables to connect telescopes, coupling large amounts of thermal and environmental noise into the signal. Additionally, recent studies have demonstrated quantum optimal interferometry both theoretically [3, 4] and experimentally [5, 6]. These works are limited in their scale as phase noise degrades the performance.
We present an experimental demonstration of optical interferometry using 85km of fibre in each arm to emulate a 170km baseline interferometer. We use a phase stabilisation system to overcome the phase noise introduced by the optical fibre. With this interferometer we are able to resolve the diameter of a pseudo-thermal source using a quantum estimator. We demonstrate this for both a temporally and spatially incoherent source. Building an interferometer with a system such as this with a 330km baseline would provide 3 orders of magnitude greater resolution than the existing largest optical interferometer, and an order of magnitude greater than the current best interferometer, the Event Horizon Telescope.
[1] DOI: 10.1080/14786447908639684
[2] DOI: 10.1086/430729
[3] DOI: 10.22331/q-2017-07-26-21
[4] DOI: 10.1103/PhysRevLett.127.130502
[5] DOI: 10.1103/PhysRevLett.123.143604
[6] DOI: 10.1038/s41467-022-32977-8
| I am the presenting author | Yes |
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