Quadrature squeezing of 10 4 spatial modes via manipulation of diffraction

We propose a general and feasible approach to realize a large number of squeezed spatial modes. This is achieved by manipulation of paraxial diffraction such that the critical wave components with most significant squeezing contribute in-phase to the spatial squeezing. As an example, we then demonstrate that it is possible to achieve localized squeezing of ∼ −1.51 dB at an area 10² μm² within a homogeneously squeezed spatial regime of w_p = 1 mm² using four-wave mixing (FWM) based on current experimental settings, corresponding to approximately 10⁴ squeezed spatial modes, which is > 10² larger in number of squeezed modes and also ∼ 6 times stronger in squeezing as compared to that obtained in the state-of-the-art experiment. We also show that the obtained extremely localized squeezed light can be directly applied to enhance the signal-to-noise ratio in quantum imaging of weakly absorbing objects by a factor of ∼ 3.5 at a spatial resolution of d ∼ 1 mm where d is the detector size.