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We present a transient response study of a semiconductor based plasmonic switch. The proposed device operates through active control and modulation of localized electron density waves, i.e., surface plasmon polaritons (SPPs) at degenerately doped In0.53Ga0.47As based PN++junctions. A set of devices is designed and fabricated, and its optical and electronic behaviors are studied both experimentally and theoretically. Optical characterization shows far-field reflectivity modulation, a result of electrical tuning of the SPPs at the PN++junctions for mid-IR wavelengths, with significant 3 dB bandwidths. Numerical studies using a self-consistent electro-optic multi-physics model are performed to uncover the temporal response of the devices’ electromagnetic and kinetic mechanisms facilitating the SPP switching at the PN++junctions. Numerical simulations show strong synergy with the experimental results, validating the claim of potential optoelectronic switching with a 3 dB bandwidth as high as 2 GHz. Thus, this study confirms that the presented SPP diode architecture can be implemented for high-speed control of SPPs through electrical means, providing a pathway toward fast all-semiconductor plasmonic devices.
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Engineering anisotropic electrodynamics at the graphene/CrSBr interface
Abstract Graphene is a privileged 2D platform for hosting confined light-matter excitations known as surface plasmon polaritons (SPPs), as it possesses low intrinsic losses and a high degree of optical confinement. However, the isotropic nature of graphene limits its ability to guide and focus SPPs, making it less suitable than anisotropic elliptical and hyperbolic materials for polaritonic lensing and canalization. Here, we present graphene/CrSBr as an engineered 2D interface that hosts highly anisotropic SPP propagation across mid-infrared and terahertz energies. Using scanning tunneling microscopy, scattering-type scanning near-field optical microscopy, and first-principles calculations, we demonstrate mutual doping in excess of 1013 cm–2holes/electrons between the interfacial layers of graphene/CrSBr. SPPs in graphene activated by charge transfer interact with charge-induced electronic anisotropy in the interfacial doped CrSBr, leading to preferential SPP propagation along the quasi-1D chains that compose each CrSBr layer. This multifaceted proximity effect both creates SPPs and endows them with anisotropic propagation lengths that differ by an order-of-magnitude between the in-plane crystallographic axes of CrSBr.
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- PAR ID:
- 10579167
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- Nature
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 16
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1038/s41467-025-56804-y
