Spin-selective reflection manipulation enabled by plasmonic guided mode resonance in out-of-plane folded metamirrors

Area of Science:

• Plasmonics
• Metamaterials
• Chiroptical phenomena

Background:

• Out-of-plane plasmonic chiral systems offer advantages for manipulating chiroptical effects due to their intrinsic chirality.
• Existing systems often require complex fabrication or lack precise control over spin-selective optical properties.

Purpose of the Study:

• To develop a chiral metamirror with an out-of-plane folded design using nano-kirigami.
• To achieve spin-selective reflection by exciting nonlocal plasmonic guided mode resonances (GMRs).
• To enable independent control over reflection amplitude and operating wavelength for circularly polarized light (CPL).

Main Methods:

• Fabrication of a chiral metamirror utilizing the nano-kirigami method with an out-of-plane folded design.
• Exploitation of out-of-plane mirror symmetry breaking to excite nonlocal plasmonic GMRs.
• Adjustment of out-of-plane structural height to control magnetic field excitation intensity for uncoupled CPL.

Main Results:

• Successful excitation of GMRs leading to spin-selective reflection of CPL.
• Demonstrated independent manipulation of reflection amplitude by adjusting structural height, while coupled CPL remained unaffected.
• Achieved proportional adjustment of resonant wavelength with changes in the dielectric layer's refractive index.

Conclusions:

• The developed chiral metamirror provides a straightforward and controllable mechanism for manipulating GMRs and achieving optical polarization selectivity.
• The independent control over amplitude and wavelength offers potential for applications in spin-selective optical encryption and gradient imaging.
• This methodology holds promise for advancements in optical information transfer, imaging, and computing.