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arXiv · 2609.34224

Surface-Normal Electric Spin in Obliquely Excited Parallel-Slit SPP Fields

Naoki Ichiji
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Abstract

Handedness-dependent light-matter interactions require control of local electric-field rotation, but generating controlled surface-normal spin textures is difficult under oblique illumination. Here, we show that oblique s-polarized illumination of a periodic array of parallel slits produces spatially alternating surface-normal electric spin, with its period continuously tunable by the incidence angle. We further show that the spin texture changes qualitatively between substrate- and air-side excitation depending on whether the SPP field interferes with the excitation field. Under substrate-side excitation, the spin distribution follows the conventional spin-flow relation, whereas under air-side excitation, interference between the SPP and excitation fields produces a distinct spatial periodicity and allows the spin extrema to coincide with the field-intensity maxima. A simple interference model reproduces these contrasting spin textures.

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Naoki Ichiji. 2026-09-28. Surface-Normal Electric Spin in Obliquely Excited Parallel-Slit SPP Fields. https://arxiv.org/abs/2609.34224

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