Properties of Ideal Flat Metalenses

McClung, Andrew; Mansouree, Mahdad; Samudrala, Sarath; Arbabi, Amir

doi:10.1364/cleo_qels.2020.fm1r.1

Cited by 4 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An ideal metalens is a local metalens that directs all the normally incident power to its focal spot without any spherical aberrations. [ 39 ] The focal spots of ideal metalenses with an NA smaller than 0.8 can be well approximated with an Airy disk. [ 39 ] We used the focal spot data in Figure 4b to calculate the modulation transfer function (MTF) of the metalenses.…”

Section: Resultsmentioning

confidence: 99%

“…[ 39 ] The focal spots of ideal metalenses with an NA smaller than 0.8 can be well approximated with an Airy disk. [ 39 ] We used the focal spot data in Figure 4b to calculate the modulation transfer function (MTF) of the metalenses. The MTFs of the NIL and EBL metalenses, as well as the simulated MTF of a diffraction‐limited ideal metalens, are shown in Figure 4c.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Visible Metalenses with High Focusing Efficiency Fabricated Using Nanoimprint Lithography

McClung,

Torfeh,

Einck

et al. 2023

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

Metasurfaces enable precise control over the properties of light and hold promise for commercial applications. However, fabricating visible metasurfaces suitable for high‐volume production is challenging and requires scalable processes. Nanoimprint lithography is a cost‐effective and high‐throughput technique that can meet this scalability requirement. This work presents a mask‐templating nanoimprint lithography process for fabricating metasurfaces with varying fill factors and negligible wavefront aberrations using composite stamps. As a proof‐of‐concept, a 6 mm diameter metalens formed of silicon nitride nano‐posts with a numerical aperture of 0.2 that operates at 550 nm is demonstrated. The nanoimprinted metalens achieves a peak focusing efficiency of (81 ± 1)%, comparable to the control metalens made with electron beam lithography with a focusing efficiency of (89 ± 1)%. Spatially resolved deflection efficiency and wavefront data, which informs design and process optimization, is also presented. These results highlight nanoimprint lithography as a cost‐effective, scalable method for visible metasurface fabrication that has potential for widespread adoption in consumer electronics and imaging systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Visible Metalenses with High Focusing Efficiency Fabricated Using Nanoimprint Lithography

McClung,

Torfeh,

Einck

et al. 2023

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…The desired output field E d was selected to be the field of an ideal, spherical-aberration-free flat lens (see Methods). To expedite the simulations, symmetric boundary conditions were used along both x and y axes, reducing the simulation volume by a factor of 4. The simulations were run until the results converged, and then the fields were converted from time to frequency domains using the method of ref .…”

Section: Resultsmentioning

confidence: 99%

“…is the local deflection angle of the metasurface, and ϕ = tan −1 (y/x) (see Figure S14). 44 Field Interpolation. The FDTD solver calculates fields on a rectangular grid (Yee grid).…”

Section: ■ Discussionmentioning

confidence: 99%

Large-Scale Parametrized Metasurface Design Using Adjoint Optimization

et al. 2021

Self Cite

View full text Add to dashboard Cite

Optical metasurfaces are planar arrangements of subwavelength meta-atoms that implement a wide range of transformations on incident light. The design of efficient metasurfaces requires that the responses of and interactions among meta-atoms are accurately modeled. Conventionally, each meta-atom’s response is approximated by that of a meta-atom located in a periodic array. Although this approximation is accurate for metastructures with slowly varying meta-atoms, it does not accurately model the complex interactions among meta-atoms in more rapidly varying metasurfaces. Optimization-based design techniques that rely on full-wave simulations mitigate this problem but thus far have been mostly applied to topology optimization of small metasurfaces. Here, we describe an adjoint-optimization-based design technique that uses parametrized meta-atoms. Our technique has a lower computational cost than topology optimization approaches, enabling the design of large-scale metasurfaces that can be readily fabricated. As proof of concept, we present the design and experimental demonstration of high numerical aperture metalenses with significantly higher efficiencies than their conventionally designed counterparts.

show abstract

“…3a) with a free-space wavelength of λ 0 =850 nm. The desired output field E d was selected to be the field of an ideal, spherical-aberration-free flat lens (see Methods) 44 . To expedite the simulations, symmetric boundary conditions were used along both x and y axes, reducing the simulation volume by a factor of four.…”

Section: Metalens Design Examplementioning

confidence: 99%

Large-scale parameterized metasurface design using adjoint optimization

Mansouree,

McClung,

Samudrala

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Optical metasurfaces are planar arrangements of subwavelength meta-atoms that implement a wide range of transformations on incident light. The design of efficient metasurfaces requires that the responses of and interactions among meta-atoms are accurately modeled. Conventionally, each meta-atom's response is approximated by that of a meta-atom located in a periodic array. Although this approximation is accurate for metastructures with slowly varying meta-atoms, it does not accurately model the complex interactions among meta-atoms in more rapidly varying metasurfaces.Optimization-based design techniques that rely on full-wave simulations mitigate this problem but thus far have been mostly applied to topology optimization of small metasurfaces. Here, we describe an adjoint-optimization-based design technique that uses parameterized meta-atoms. Our technique has a lower computational cost than topology optimization approaches, enabling the design of large-scale metasurfaces that can be readily fabricated. As proof of concept, we present the design and experimental demonstration of high numerical aperture metalenses with significantly higher efficiencies than their conventionally-designed counterparts.

show abstract

Properties of Ideal Flat Metalenses

Abstract: We derive image space fields of ideal flat metalenses, which differ significantly from those of refractive lenses, and use them to determine the modulation transfer function, depth of focus and spectral bandwidth of flat metalenses.

Cited by 4 publications

References 4 publications

Visible Metalenses with High Focusing Efficiency Fabricated Using Nanoimprint Lithography

Visible Metalenses with High Focusing Efficiency Fabricated Using Nanoimprint Lithography

Large-Scale Parametrized Metasurface Design Using Adjoint Optimization

Large-scale parameterized metasurface design using adjoint optimization

Contact Info

Product

Resources

About