  We propose a theoretical scheme to enhance the sensitivity of a quantum
fiber-optical gyroscope (QFOG) via a non-Gaussian-state probe based on
quadrature measurements of the optical field. The non-Gaussian-state probe
utilizes the product state comprising a photon-added coherent state (PACS) with
photon excitations and a coherent state CS. We study the sensitivity of the
QFOG, and find that it can be significantly enhanced through increasing the
photon excitations in the PACS probe. We investigate the influence of photon
loss on the performance of QFOG and demonstrate that the PACS probe exhibits
robust resistance to photon loss. Furthermore, we compare the performance of
the QFOG using the PACS probe against two Gaussian-state probes: the CS probe
and the squeezed state (SS) probe and indicate that the PACS probe offers a
significant advantage in terms of sensitivity, regardless of photon loss, under
the constraint condition of the same total number of input photons.
Particularly, it is found that the sensitivity of the PACS probe can be three
orders of magnitude higher than that of two Gaussian-state probes for certain
values of the measured parameter. The capabilities of the non-Gaussian state
probe on enhancing the sensitivity and resisting photon loss could have a
wide-ranging impact on future high-performance QFOGs.
