Limits to Squeezing of Quantum Fluctuations

David D. Crouch, Samuel L. Braunstein

We perform discrete-mode calculations for a parametric amplifier with a quantum pump and discuss some of the limitations on calculations of this sort in quantum optics. We calculate corrections to the squeezing due to pump quantum fluctuations to order N${\ifmmode\bar\else\textasciimacron\fi{}}^{\mathrm{\ensuremath{-}}2}$, for a pump initially in a coherent state with average photon number N\ifmmode\bar\else\textasciimacron\fi{}. We find that the limit to the variance of the squeezed quadrature due to the quantum nature of the pump goes as N${\ifmmode\bar\else\textasciimacron\fi{}}^{\mathrm{\ensuremath{-}}1/2}$. .AE

Anonymous

Bogdan Mielnik, Jesús Fuentes

Vladislav N. Beskrovnyy, Mikhail I. Kolobov

We numerically investigate the role of quantum fluctuations in superresolution of optical objects. First, we confirm that when quantum fluctuations are not taken into account, one can easily improve the resolution by one order of magnitude beyond the diffraction limit. Then we investigate the standard quantum limit of superresolution which is achieved for illumination of an object by a light wave in a coherent state. We demonstrate that this limit can be beyond the diffraction limit. Finally, we show that further improvement of superresolution beyond the standard quantum limit is possible using the object illumination by a multimode squeezed light.

Z. Ficek, R. Tanaś

Anqi Zhang, Zeyang Liao, Rongxin Chen +1 more

Abbe’s diffraction limit restricts the resolution of an optical imaging and lithography system. A coherent Rabi oscillation is shown to be able to overcome the diffraction limit in both optical and atom lithography. In previous studies, semiclassical theory is applied, where the driving field is treated as a classical light, and quantum fluctuation is neglected. Here, we show that the quantum fluctuation may reduce the visibility of the superresolution pattern. However, by squeezing the photon number fluctuation, we are able to significantly increase its visibility.