Spatial shaping for generating arbitrary optical dipole traps for ultracold degenerate gases.
Spatial shaping for generating arbitrary optical dipole traps for ultracold degenerate gases.
复制标题
用于为超冷简并气体生成任意光学偶极子陷阱的空间整形。
DOI：
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发表时间：
2014
影响因子：
1.6
通讯作者：
W. T. Hill
中科院分区：
文献类型：
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作者：
Jeffrey G. Lee;W. T. Hill
我们提出了两种空间整形方法-相位和振幅-用于创建超冷中性原子的二维光学偶极势。当与由聚焦光束形成的吸引或排斥高斯片相结合时，原子被困在三维空间中，导致平面限制与任意网络的潜力-自由空间原子芯片。第一种方法利用了广义相衬技术的适应，以转换嵌入在穿过相位掩模后的光束中的相位结构，在图像平面中的相同的强度分布。相位掩模和必要的相衬滤光器可以化学蚀刻到光学材料中（例如，熔融石英）或用空间光调制器实现;蚀刻提供最高质量，而空间光调制器实现原型制作和实时结构修改。这种方法被证明对一个系综的热原子。振幅整形是可能的，当潜在的结构是作为一个不透明的掩模在偶极陷阱光束的路径，然后通过成像的阴影到原子的平面上。虽然损耗更大，但这种非常简单和廉价的方法可以产生适合包含简并气体的偶极势。高质量的振幅掩模可以用标准的光刻技术生产。振幅整形在玻色-爱因斯坦凝聚体上得到了证实。
We present two spatial-shaping approaches - phase and amplitude - for creating two-dimensional optical dipole potentials for ultracold neutral atoms. When combined with an attractive or repulsive Gaussian sheet formed by an astigmatically focused beam, atoms are trapped in three dimensions resulting in planar confinement with an arbitrary network of potentials - a free-space atom chip. The first approach utilizes an adaptation of the generalized phase-contrast technique to convert a phase structure embedded in a beam after traversing a phase mask, to an identical intensity profile in the image plane. Phase masks, and a requisite phase-contrast filter, can be chemically etched into optical material (e.g., fused silica) or implemented with spatial light modulators; etching provides the highest quality while spatial light modulators enable prototyping and realtime structure modification. This approach was demonstrated on an ensemble of thermal atoms. Amplitude shaping is possible when the potential structure is made as an opaque mask in the path of a dipole trap beam, followed by imaging the shadow onto the plane of the atoms. While much more lossy, this very simple and inexpensive approach can produce dipole potentials suitable for containing degenerate gases. High-quality amplitude masks can be produced with standard photolithography techniques. Amplitude shaping was demonstrated on a Bose-Einstein condensate.