Luneburg lens composed of sunflower-type graded photonic Crystals

Sun, Xin; Wu, Yulong; Liu, Wei; Yan-Ming, Hao; Jiang, Liudi

doi:10.1016/j.optcom.2013.11.022

Cited by 24 publications

(18 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the EMT, in order to realize this refractive index profile using a piecewise-constant approximation and a set of multimaterial nanowires, the required effective permittivity for each nanowire can be obtained as ref. 8 : where ε host is the host medium permittivity, ff is the filling fraction and n is the required refractive index to be realized. The filling fraction can be obtained by dividing the total area of the lens by the total area occupied by nanowires.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, GRIN metamaterials are two- or three- dimensional arrays of deeply subwavelength unit-cells which realize a gradient refractive index profile thus enabling bending the light waves in peculiar ways 4 – 6 . The extensive research on gradient metamaterials has led to a variety of flat and bulk optical components for different applications including focusing lenses 7 , 8 , beam steering 9 – 11 and holographic devices 12 , 13 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrically Tunable Metamaterials Based on Multimaterial Nanowires Incorporating Transparent Conductive Oxides

Salary

Mosallaei

2017

Sci Rep

View full text Add to dashboard Cite

We present novel design approaches for metasurfaces and metamaterials with electrical tunability offering real-time manipulation of light and serving as multifunctional devices in near-infrared frequency regime (at the specific wavelength of 1.55 μm). For this purpose, we integrate indium-tin-oxide (ITO) as a tunable electro-optical material into multimaterial nanowires with metal-oxide-semiconductor and metal-insulator-metal configurations. In particular, an active metasurface operating in the transmission mode is designed which allows for modulation of the transmitted light phase over 280 degrees. This large phase modulation is afforded in the cost of low transmission efficiency. We demonstrate the use of such active metasurfaces for tunable bending and focusing in free-space. Moreover, we investigate the implementation of this material in deeply subwavelength multimaterial nanowires, which can yield strong variations in the effective refractive index by the virtue of internal homogenization enabling tunability of the performance in gradient refractive index metamaterials. In the theoretical modeling of these structures, we adopt a hierarchical multiscale approach by linking drift-diffusion transport model with the electromagnetic model which rigorously characterizes the electro-optical effects.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrically Tunable Metamaterials Based on Multimaterial Nanowires Incorporating Transparent Conductive Oxides

Salary

Mosallaei

2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The ray-tracing calculations indicate that the truncation of the lens has a limited effect on the performance of the lens as long as the incident rays are within the left and right edges of the lens. GRIN lenses have been implemented by multilayer structures [37][38][39], varying the guiding layer's thickness [40][41][42], and GPC [43,44]. We implement the truncated lens with a GPC structure as shown in Fig.…”

Section: Flattened Luneburg Couplermentioning

confidence: 99%

Coupling Si3N4 waveguide to SOI waveguide using transformation optics

Badri¹,

Gilarlue²

2020

Optics Communications

View full text Add to dashboard Cite

Silicon nitride (Si3N4) planar waveguide platform combined with silicon-on-insulator (SOI) devices offer a whole new generation of system-on-chip applications. Therefore, efficient coupling of an Si3N4 waveguide to an SOI waveguide is essential. We present a coupler to interface a 1.8 µm-wide Si3N4 waveguide to a 0.5 µm-wide SOI waveguide based on the focusing property of the Luneburg lens. In order to match the refractive indices of the waveguides with the edges of the lens, one side of the lens is flattened with quasi-conformal transformation optics. The designed coupler is implemented by graded photonic crystals. The three-dimensional numerical simulations indicate that the 1.93 µm-long coupler has an average coupling loss of 0.13 dB in the C-band.

show abstract

“…TM lens can lead to a larger transmission bandwidth and better focusing characteristics compared with those of TE lens [27]. In this work, we mainly study the issue of TM polarization.…”

Section: Basic Structurementioning

confidence: 99%

Design of an Electrically Tunable Micro-Lens Based on Graded Photonic Crystal

Sun

Wang

et al. 2018

Crystals

View full text Add to dashboard Cite

A micro-lens with an adjustable focal length (FL) is designed by using Graded Photonic Crystal (GPC) structures and a Polymer Dispersed Liquid Crystal (PDLC) material. The GPCs are formed by gradually changing the radius of the polymer rods in the Photonic Crystal (PC) with square lattices of polymer rods in the background of Liquid Crystals (LCs). The electrically tunable focusing characteristics of the micro-lens are investigated by loading a continuous voltage source to change the LC rotation angle. The sensitivity of the focal shift in terms of LCs tilting angle is 0.152 λ(nm/deg). Moreover, the effect of the defects and deviations on the focusing characteristics are also analyzed. This research is crucial for future applications of the proposed device in the integrated photonics and adaptive optics.

show abstract

Luneburg lens composed of sunflower-type graded photonic Crystals

Cited by 24 publications

References 20 publications

Electrically Tunable Metamaterials Based on Multimaterial Nanowires Incorporating Transparent Conductive Oxides

Electrically Tunable Metamaterials Based on Multimaterial Nanowires Incorporating Transparent Conductive Oxides

Coupling Si3N4 waveguide to SOI waveguide using transformation optics

Design of an Electrically Tunable Micro-Lens Based on Graded Photonic Crystal

Contact Info

Product

Resources

About