Optimization of transverse unidirectional scattering by morphology modification of irregular V-shaped silicon nanoantennas

Abstract

A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation. Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency. However, due to the limitations of regular shapes, it is challenging to meet high-precision design requirements. Irregular shape design allows for a broader range of adjustments, but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima. This paper proposes an irregular fine-tuning scheme for regular V-shaped silicon nanoscale antennas that combines the advantages of both approaches. Firstly, the regular V-shaped nanoantenna is tuned to generate transverse unidirectional scattering and then transformed into a binary image. Subsequently, the kernel geometry is fixed while the morphology is modified by a surface contour method to form irregular V-shapes. Finally, those irregular V-shapes are input into a pre-trained predictor cascaded by Bayesian optimization (BO) and the nanoantenna’s shape is progressively updated by minimizing the mean squared error (MSE) between the target scattering and the predicted scattering of irregular nanostructures. The results demonstrate that the optimized irregular V-shaped nanoantennas exhibit perfect transverse directional scattering and the scattering tail in the opposite direction is greatly shrunk, the MSE of its scattering compared to the ideal unidirectional scattering has decreased by approximately 29% after optimization. Our findings can promote all-dielectric nanoantennas with specific directional scattering in integrated nanophotonics circuits and sensors.

References

[1] Li N, Lai Y, Lam S H, et al.. Directional control of light with nanoantennas. Advanced optical materials, 2021, 9(1): 2001081 J]

[2] Zhu F, Sanz-Paz M, Fernandez-Dominguez A I, et al.. Optical ultracompact directional antennas based on a dimer nanorod structure. Nanomaterials, 2022, 12(16): 2841 J]

[3] Ai B, Sun Y, Zhao Y. Plasmonic hydrogen sensors. Small, 2022, 18(25): 2107882 J]

[4] Bag A, Neugebauer M, Mick U, et al.. Towards fully integrated photonic displacement sensors. Nature communications, 2020, 11(1): 2915 J]

[5] Wersall M, Verre R, Svedendahl M, et al.. Directional nanoplasmonic antennas for self-referenced refractometric molecular analysis. The journal of physical chemistry C, 2014, 118(36): 21075-21080 J]

[6] LI Y, BI X, YOU Q, et al. Strong coupling with directional scattering features of metal nanoshells with monolayer WS2 heterostructures[J]. Applied physics letters, 2022, 121(2).

[7] Zhang T, Li X, Xu J, et al.. Subwavelength silicon nanoblocks for directional emission manipulation. Nanomaterials, 2020, 10(6): 1242 J]

[8] Batelbek H, Abadula R, Li P, et al.. Efficient directional forward scattering by a single Cu@Si core-shell nanoparticle in visible regions. Optical materials, 2024, 148: 114895 J]

[9] Lv J, Ren Y, Wang D, et al.. Multi-wavelength unidirectional forward scattering properties of the arrow-shaped gallium phosphide nanoantenna. JOSA A, 2023, 40(11): 2034-2044 J]

[10] Albella P, Shibanuma T, Maier S A. Switchable directional scattering of electromagnetic radiation with subwavelength asymmetric silicon dimers. Scientific reports, 2015, 5(1): 18322 J]

[11] Matsumori A, Sugimoto H, Fujii M. Unidirectional transverse light scattering in notched silicon nanosphere. Laser & photonics reviews, 2023, 17(8): 2300314 J]

[12] Meng Y, Chen Y, Lu L, et al.. Optical meta-waveguides for integrated photonics and beyond. Light: science & applications, 2021, 10(1): 1-44 J]

[13] Bag A, Neugebauer M, Wozniak P, et al.. Transverse kerker scattering for angstrom localization of nanoparticles. Physical review letters, 2018, 121(19): 193902 J]

[14] Zhang Z, Xiang Y, Xu W, et al.. Broadband transverse unidirectional scattering and large range nanoscale displacement measuring based on the interaction between a tightly focused azimuthally polarized beam and a silicon hollow nanostructure. Optics express, 2023, 31(10): 15372-15383 J]

[15] Li C, Ouayng X, Sun J, et al.. Transverse scattering from nanodimers tunable with generalized cylindrical vector beams. Laser & photonics reviews, 2023, 17(6): 2200867 J]

[16] Yu Y, Liu J, Yu Y, et al.. Broadband unidirectional transverse light scattering in a V-shaped silicon nanoantenna. Optics express, 2022, 30(5): 7918-7927 J]

[17] An S, Zheng B, Shalaginov M Y, et al.. Deep learning modeling approach for metasurfaces with high degrees of freedom. Optics express, 2020, 28(21): 31932-31942 J]

[18] Park J, Kim S, Nam D W, et al.. Free-form optimization of nanophotonic devices: from classical methods to deep learning. Nanophotonics, 2022, 11(9): 1809-1845 J]

[19] An S, Zheng B, Tang H, et al.. Multifunctional metasurface design with a generative adversarial network. Advanced optical materials, 2021, 9(5): 2001433 J]

[20] LI W, BARATI SEDEH H, TSVETKOV D, et al. Machine learning for engineering meta-atoms with tailored multipolar resonances[J]. Laser & photonics reviews, 2024: 2300855.

[21] Ma W, Liu Z, Kudyshev Z A, et al.. Deep learning for the design of photonic structures. Nature photonics, 2021, 15(2): 77-90 J]

[22] XIONG B, XU Y, LI W, et al. Deep learning design for multiwavelength infrared image sensors based on dielectric freeform metasurface[J]. Advanced optical materials, 2023: 2302200.

[23] Liu W, Wang X, Zeng M. A nested U-shaped network for accurately predicting directional scattering of all-dielectric nanostructures. Optics letters, 2022, 47(19): 5112-5115 J]

[24] Qie J, Khoram E, Liu D, et al.. Real-time deep learning design tool for far-field radiation profile. Photonics research, 2021, 9(4): B104-B108 J]

[25] Wiecha P R, Majorel C, Girard C, et al.. Design of plasmonic directional antennas via evolutionary optimization. Optics express, 2019, 27(20): 29069-29081 J]

[26] Qin F, Zhang D, Liu Z, et al.. Designing metal-dielectric nanoantenna for unidirectional scattering via Bayesian optimization. Optics express, 2019, 27(21): 31075-31086 J]

[27] YAN J, ZHU D, BAO Y, et al. Design of multifunctional color routers with Kerker switching using generative adversarial networks[J]. Laser & photonics reviews, 2024: 2300592.

[28] Borghesi A, Guizzetti G. Handbook of optical constants of solids, 1985, New York, Academic 445-464 M]

[29] Qin X, Zhang Z, Huang C, et al.. U2-Net: going deeper with nested U-structure for salient object detection. Pattern recognition, 2020, 106: 107404 J]

[30] Evlyukhin A B, Fischer T, Reinhardt C, et al.. Optical theorem and multipole scattering of light by arbitrarily shaped nanoparticles. Physical review B, 2016, 94(20): 20543 J]