An SU(1,1) interferometer uses a sequence of two optical parametric amplifiers for achieving sub-shot-noise sensitivity to a phase shift introduced in between. We present the first realization of a wide-field SU(1,1) interferometer, where the use of a focusing element enables spatially multimode operation within a broad angle. Over this angle, the interference phase is found to be flat. This property is important for the high sensitivity to the phase front disturbance. Further, −4.3±0.7 dB quadrature squeezing, an essential requirement to the high sensitivity, is experimentally demonstrated for plane-wave modes inside the interferometer. Such an interferometer is useful not only for quantum metrology, but also in remote sensing, enhanced sub-shot-noise imaging, and quantum information processing.
@article{arxiv.1905.03143,
title = {Wide-field SU(1,1) interferometer},
author = {G. Frascella and E. E. Mikhailov and N. Takanashi and R. V. Zakharov and O. V. Tikhonova and M. V. Chekhova},
journal= {arXiv preprint arXiv:1905.03143},
year = {2019}
}