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Macroscopic invisibility cloaking of visible light.

Chen X, Luo Y, Zhang J, Jiang K, Pendry JB, Zhang S - Nat Commun (2011)

Bottom Line: All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths.The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale of centimetres and millimetres.Our work opens avenues for future applications with macroscopic cloaking devices.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.

ABSTRACT
Invisibility cloaks, which used to be confined to the realm of fiction, have now been turned into a scientific reality thanks to the enabling theoretical tools of transformation optics and conformal mapping. Inspired by those theoretical works, the experimental realization of electromagnetic invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths. Here, we report the first realization of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale of centimetres and millimetres. Our work opens avenues for future applications with macroscopic cloaking devices.

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Related in: MedlinePlus

Illustration of the transformation from real to virtual space and cloaking design.In the transformation, a triangular cross-section in a virtual space (a) filled with isotropic materials is mapped to a quadrilateral (brown region in (b) with uniform and anisotropic optical properties. The cloaked region is defined by the small grey triangle wherein objects can be rendered invisible. (c) A photograph of the triangular cloak, which consists of two calcite prisms glued together, with the geometrical parameters indicated in the figure. The dimension of the cloak along z direction is 2 cm. The optical axis, represented by red arrows, forms an angle of 30° with the glued interface.
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f1: Illustration of the transformation from real to virtual space and cloaking design.In the transformation, a triangular cross-section in a virtual space (a) filled with isotropic materials is mapped to a quadrilateral (brown region in (b) with uniform and anisotropic optical properties. The cloaked region is defined by the small grey triangle wherein objects can be rendered invisible. (c) A photograph of the triangular cloak, which consists of two calcite prisms glued together, with the geometrical parameters indicated in the figure. The dimension of the cloak along z direction is 2 cm. The optical axis, represented by red arrows, forms an angle of 30° with the glued interface.

Mentions: The cloak is based on a recent theoretical work20 that indicates that a carpet cloak can be achieved with spatially homogeneous anisotropic dielectric materials. A schematic of the triangular cloaking design is shown in Figure 1, where a virtual space with a triangular cross-section of height H2 and filled with an isotropic material of permittivity ɛ and μ (μ=1; blue region in Fig. 1a) is mapped to a quadrilateral region in the physical space with anisotropic electromagnetic properties ɛ′ and μ′ (brown region in Fig. 1b). Thus, the cloaked region is defined by the small grey triangle of height H1 and half-width d. Mathematically, the transformation is defined by 1 where (x′, y′, z′) and (x, y, z) correspond to the coordinates of the physical space and virtual space, respectively. Applying this coordinate transformation to Maxwell's equations, we obtain the corresponding electromagnetic parameters of the quadrilateral cloaking region: 2 where 3


Macroscopic invisibility cloaking of visible light.

Chen X, Luo Y, Zhang J, Jiang K, Pendry JB, Zhang S - Nat Commun (2011)

Illustration of the transformation from real to virtual space and cloaking design.In the transformation, a triangular cross-section in a virtual space (a) filled with isotropic materials is mapped to a quadrilateral (brown region in (b) with uniform and anisotropic optical properties. The cloaked region is defined by the small grey triangle wherein objects can be rendered invisible. (c) A photograph of the triangular cloak, which consists of two calcite prisms glued together, with the geometrical parameters indicated in the figure. The dimension of the cloak along z direction is 2 cm. The optical axis, represented by red arrows, forms an angle of 30° with the glued interface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3105339&req=5

f1: Illustration of the transformation from real to virtual space and cloaking design.In the transformation, a triangular cross-section in a virtual space (a) filled with isotropic materials is mapped to a quadrilateral (brown region in (b) with uniform and anisotropic optical properties. The cloaked region is defined by the small grey triangle wherein objects can be rendered invisible. (c) A photograph of the triangular cloak, which consists of two calcite prisms glued together, with the geometrical parameters indicated in the figure. The dimension of the cloak along z direction is 2 cm. The optical axis, represented by red arrows, forms an angle of 30° with the glued interface.
Mentions: The cloak is based on a recent theoretical work20 that indicates that a carpet cloak can be achieved with spatially homogeneous anisotropic dielectric materials. A schematic of the triangular cloaking design is shown in Figure 1, where a virtual space with a triangular cross-section of height H2 and filled with an isotropic material of permittivity ɛ and μ (μ=1; blue region in Fig. 1a) is mapped to a quadrilateral region in the physical space with anisotropic electromagnetic properties ɛ′ and μ′ (brown region in Fig. 1b). Thus, the cloaked region is defined by the small grey triangle of height H1 and half-width d. Mathematically, the transformation is defined by 1 where (x′, y′, z′) and (x, y, z) correspond to the coordinates of the physical space and virtual space, respectively. Applying this coordinate transformation to Maxwell's equations, we obtain the corresponding electromagnetic parameters of the quadrilateral cloaking region: 2 where 3

Bottom Line: All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths.The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale of centimetres and millimetres.Our work opens avenues for future applications with macroscopic cloaking devices.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.

ABSTRACT
Invisibility cloaks, which used to be confined to the realm of fiction, have now been turned into a scientific reality thanks to the enabling theoretical tools of transformation optics and conformal mapping. Inspired by those theoretical works, the experimental realization of electromagnetic invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths. Here, we report the first realization of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale of centimetres and millimetres. Our work opens avenues for future applications with macroscopic cloaking devices.

Show MeSH
Related in: MedlinePlus