Full characterization of the quantum spiral bandwidth of entangled biphotons
Full characterization of the quantum spiral bandwidth of entangled biphotons
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DOI：
10.1103/physreva.83.033816
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发表时间：
2011-03-15
影响因子：
2.9
通讯作者：
Barnett, Stephen M.
中科院分区：
文献类型：
--
作者：
Miatto, Filippo M.;Yao, Alison M.;Barnett, Stephen M.
自发参量下转换已被证明是一种可靠的纠缠光子源。在众多被证明是纠缠态的性质中，轨道角动量是我们研究的重点。我们特别研究了高斯泵浦光束产生的双光子态。我们推导了下转换拉盖尔-高斯光束的轨道角动量l和径向动量p同时相关的表达式。例如，我们的结果允许我们在不受光束几何形状限制的情况下计算螺旋带宽：l、p和光束宽度都是自由参数。此外，我们还证明，使用通常的近轴和共线近似，可以推导出相关性的完全解析表达式。
Spontaneous parametric down-conversion has been shown to be a reliable source of entangled photons. Among the wide range of properties shown to be entangled, it is the orbital angular momentum that is the focus of our study. We investigate, in particular, the bi-photon state generated using a Gaussian pump beam. We derive an expression for the simultaneous correlations in the orbital angular momentum, l, and radial momentum, p, of the down-converted Laguerre-Gaussian beams. Our result allows us, for example, to calculate the spiral bandwidth with no restriction on the geometry of the beams: l, p, and the beam widths are all free parameters. Moreover, we show that, with the usual paraxial and collinear approximations, a fully analytic expression for the correlations can be derived.