Super-resolved angular displacement estimation based upon a Sagnac interferometer and parity measurement


Jian-Dong Zhang, Zi-Jing Zhang, Long-Zhu Cen, Jun-Yan Hu and Yuan Zhao


“Super-resolved angular displacement estimation is of crucial significance to the field
of quantum information processing. Here we report an estimation protocol based on a Sagnac
interferometer fed by a coherent state carrying orbital angular momentum. In a lossless scenario,
through the use of parity measurement, our protocol can achieve a 4`-fold super-resolved output
with quantum number `; meanwhile, a shot-noise-limited sensitivity saturating the quantum
Cramér-Rao bound is reachable. We also consider the effects of several realistic factors, including
nonideal state preparation, photon loss, and inefficient measurement. Finally, with mean photon
number 𝑁¯ = 2.297 and ℓ = 1 taken, we experimentally demonstrate a super-resolved effect of
angular displacement with a factor of 7.88.”

Link to Publications Page

Publication: Optics Express
Issue/Year: Vol. 28, Issue 3, pp. 4320-4332
DOI: 10.1364/OE.384082