M. Zhang
College of William & Mary
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Publication
Featured researches published by M. Zhang.
Physical Review A | 2017
M. Zhang; Melissa A. Guidry; R. Nicholas Lanning; Zhihao Xiao; Jonathan P. Dowling; Irina Novikova; Eugeniy E. Mikhailov
We study a squeezed vacuum field generated in hot Rb vapor via the polarization self-rotation effect. Our previous experiments showed that the amount of observed squeezing may be limited by the contamination of the squeezed vacuum output with higher-order spatial modes, also generated inside the cell. Here, we demonstrate that the squeezing can be improved by making the light interact several times with a less dense atomic ensemble. With optimization of some parameters we can achieve up to -2.6 dB of squeezing in the multi-pass case, which is 0.6 dB improvement compared to the single-pass experimental configuration. Our results show that other than the optical depth of the medium, the spatial mode structure and cell configuration also affect the squeezing level.
Physical Review A | 2017
R. Nicholas Lanning; Zhihao Xiao; M. Zhang; Irina Novikova; Eugeniy E. Mikhailov; Jonathan P. Dowling
We present a general, Gaussian spatial mode propagation formalism for describing the generation of higher order multi-spatial-mode beams generated during nonlinear interactions. Furthermore, to implement the theory, we simulate optical angular momentum transfer interactions, and show how one can optimize the interaction to reduce the undesired modes. Past theoretical treatments of this problem have often been phenomenological, at best. Here we present an exact solution for the single-pass no-cavity regime, in which the the nonlinear interaction is not overly strong. We apply our theory to two experiments, with very good agreement, and give examples of several more configurations, easily tested in the laboratory.
Optics Letters | 2013
M. Zhang; Joseph Soultanis; Irina Novikova; Eugeniy E. Mikhailov
We demonstrated that by using a pump field with nonzero orbital angular momentum (OAM) in the polarization self-rotation squeezing process it is possible to generate a squeezed vacuum optical field with the matching OAM. We found a similar level of maximum quantum noise reduction for a first-order Laguerre-Gaussian pump beam and a regular Gaussian pump beam, even though the optimal operational conditions differed in these two cases. Also, we investigated the effect of self-defocusing on the level of the vacuum squeezing by simultaneously monitoring the minimum quantum noise level and the output beam transverse profile at various pump laser powers and atomic densities and found no direct correlations between the increased beam size and the degree of measured squeezing.
Physical Review A | 2017
Zhihao Xiao; R. Nicholas Lanning; M. Zhang; Irina Novikova; Eugeniy E. Mikhailov; Jonathan P. Dowling
Within the second-quantization framework, we develop a formalism for describing a spatially multimode optical field diffracted through a spatial mask and show that this process can be described as an effective interaction between various spatial modes. We demonstrate a method to calculate the quantum state in the diffracted optical field for any given quantum state in the incident field. Using numerical simulations, we also show that with single-mode squeezed-vacuum state input, the prediction of our theory is in qualitative agreement with our experimental data. We also give several additional examples of how the theory works, for various quantum input states, which may be easily tested in the lab; including two single-mode squeezed vacuums, single- and two-photon inputs, where we show the diffraction process produces two-mode squeezed vacuum, number-path entanglement and a Hong-Ou-Mandel-like effect--analogous to a beam splitter.
conference on lasers and electro optics | 2016
M. Zhang; Irina Novikova; Eugeniy E. Mikhailov; R. Nicholas Lanning; Zhihao Xiao; Jonathan P. Dowling
We study experimentally and theoretically the role of internally-generated higher-order Laguerre-Gauss modes in measurements of squeezed vacuum produced via polarization self-rotation interaction of an ensemble of Rb atoms and a strong linearly polarized laser field.
Frontiers in Optics | 2015
Zhihao Xiao; R. Nicholas Lanning; M. Zhang; Irina Novikova; Eugeniy E. Mikhailov; Jonathan P. Dowling
We second quantize multiple orders of Gaussian modes. We analytically examine the interaction between modes when space is limited and the orthogonality between modes is destroyed. We numerically simulate the effect of interaction on squeezed vacuum states and show it matches experimental data.
Frontiers in Optics | 2013
M. Zhang; Joseph Soultanis; Irina Novikova; Eugeniy E. Mikhailov
A vortex beam profile of squeezed vacuum is generated in Rb vapor cell with the beam shape by placing a phase mask in the input pump field. Effect of self-focusing on observed squeezing is investigated.
Physical Review A | 2016
M. Zhang; R. Nicholas Lanning; Zhihao Xiao; Jonathan P. Dowling; Irina Novikova; Eugeniy E. Mikhailov
conference on lasers and electro optics | 2018
Irina Novikova; M. Zhang; Melissa A. Guidry; Eugeniy E. Mikhailov; R. Nicholas Lanning; Zhihao Xiao; Jonathan P. Dowling
arXiv: Optics | 2018
Zhihao Xiao; R. Nicholas Lanning; M. Zhang; Irina Novikova; Eugeniy E. Mikhailov; Jonathan P. Dowling