Ultrabroadband optical circular polarizers consisting of double-helical nanowire structures

Yang, Ziyuan; Zhao, Ming; Lu, Peixiang; Lu, Yongfeng

doi:10.1364/ol.35.002588

Cited by 95 publications

(72 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…N-helices have been proposed several years ago [10][11][12], but certain constraints due to their principle of operation have only been studied later for the case of N = 4, 8, 12, ... [14]. We have shown that the four-fold rotational symmetry strictly eliminates off-diagonal elements in the Jones transmission and reflection matrices in circular polarization basis, provided that no diffracted orders other than the two 0-th orders occur.…”

Section: Symmetry and Reciprocitymentioning

confidence: 95%

See 1 more Smart Citation

Tapered N-helical metamaterials with three-fold rotational symmetry as improved circular polarizers

Kaschke¹,

Blome²,

Burger³

et al. 2014

Opt. Express

View full text Add to dashboard Cite

Abstract:Chiral helix-based metamaterials can potentially serve as compact and broadband circular polarizers. We have recently shown that the physics of structures composed of multiple intertwined helices, so called N-helices with N being an integer multiple of 4, is distinct from that of structures made of single circular helices (N = 1). In particular, undesired circular polarization conversion is strictly eliminated for N = 4 helices arranged on a square lattice. However, the fabrication of such structures for infrared/visible operation wavelengths still poses very significant challenges. Thus, we here revisit the possibility of reducing N from 4 to 3, which would ease micro-fabrication considerably. We show analytically that N = 3 helices arranged on a hexagonal lattice exhibit strictly vanishing circular polarization conversion. N = 3 is the smallest option as N = 2 obviously leads to linear birefringence. To additionally improve the circular-polarizer operation bandwidth and the extinction ratio while maintaining high transmission for the wanted polarization and zero conversion, we also investigate by numerical calculations N = 3 helices with tapered diameter along the helix axis. We find operation bandwidths as large as 2.4 octaves.

show abstract

Section: Symmetry and Reciprocitymentioning

confidence: 95%

“…Linear birefringence is equivalent to circular polarization conversions. By intertwining several helices in one unit cell, these conversions can be eliminated [10][11][12]. N = 2 helices (untapered and tapered [13]) exhibit even more obviously an unwanted linear birefringence.…”

Section: Introductionmentioning

confidence: 99%

Tapered N-helical metamaterials with three-fold rotational symmetry as improved circular polarizers

Kaschke¹,

Blome²,

Burger³

et al. 2014

Opt. Express

View full text Add to dashboard Cite

show abstract

“…To reduce or eliminate these unwanted polarization conversion effects, multiple (integer N) intertwined helices have previously been proposed [10,11]. For N = 2, they can be seen as the analog to the DNA double strands in biology.…”

Section: Introductionmentioning

confidence: 99%

On metamaterial circular polarizers based on metal N-helices

Kaschke¹,

Gansel²,

Wegener³

2012

Opt. Express

117

View full text Add to dashboard Cite

Metal-helix based metamaterials have been introduced as compact and broadband circular polarizers. However, the end of the metal wire together with the helix center defines an axis in space, which unavoidably breaks the rotational symmetry at the metamaterial surface. This introduces linear birefringence. Symmetry can be recovered by considering an integer number, e.g. N = 4, of intertwined helices arranged to a square array. We show that the operation principles are fundamentally different though. Metamaterial circular polarizers based on N = 4 helices, unlike single helices, inherently require absorption of the constituent metal. Otherwise, the combination of a four-fold rotational axis and time-inversion symmetry strictly forbids circular-polarizer action. Our symmetry analysis is confirmed by extensive numerical calculations comparing results for perfect electric conductors with those for a free-electron Drude metal with finite damping.

show abstract

“…Rotational symmetry, intrinsically lacking in helix geometry, can be effectively restored with a packed multihelix arrangement in a single cell by the multihelical nanowire (MHN) configuration (similar to DNA strands), which have been recently theoretically proposed 20,[25][26][27][28] . MHNs are predicted to operate as broadband circular polarizers in the visible range with high purity of circularly polarized transmitted light.…”

mentioning

confidence: 99%

Triple-helical nanowires by tomographic rotatory growth for chiral photonics

et al. 2015

View full text Add to dashboard Cite

Three dimensional helical chiral metamaterials resulted in effective manipulation of circularly polarized light in the visible infrared for advanced nanophotonics. Their potentialities are severely limited by the lack of full rotational symmetry preventing broadband operation, high signal-to-noise ratio and inducing high optical activity sensitivity to structure orientation. Complex intertwined three dimensional structures such as multiple-helical nanowires could overcome these limitations, allowing the achievement of several chiro-optical effects combining chirality and isotropy. Here we report three dimensional triple-helical nanowires, engineered by the innovative tomographic rotatory growth, on the basis of focused ion beam-induced deposition. These three dimensional nanostructures show up to 37% of circular dichroism in a broad range (500-1,000 nm), with a high signal-to-noise ratio (up to 24 dB). Optical activity of up to 8°only due to the circular birefringence is also shown, tracing the way towards chiral photonic devices that can be integrated in optical nanocircuits to modulate the visible light polarization.

show abstract

Ultrabroadband optical circular polarizers consisting of double-helical nanowire structures

Cited by 95 publications

References 15 publications

Tapered N-helical metamaterials with three-fold rotational symmetry as improved circular polarizers

Tapered N-helical metamaterials with three-fold rotational symmetry as improved circular polarizers

On metamaterial circular polarizers based on metal N-helices

Triple-helical nanowires by tomographic rotatory growth for chiral photonics

Contact Info

Product

Resources

About