Wideband polarization-independent plasmonic switch based on GST phase-change material

Area of Science:

• Photonics and Nanotechnology
• Materials Science

Background:

• Chalcogenide phase-change materials, specifically germanium-antimony-tellurium (GST), are promising for tunable plasmonic devices.
• Plasmonic devices offer unique light-matter interaction capabilities in the optical spectrum.

Purpose of the Study:

• To design and simulate a wideband plasmonic switch utilizing gold cross-shaped resonators and GST.
• To investigate the tunability of the plasmonic switch by exploiting the phase transitions of GST.
• To evaluate the performance of the switch concerning extinction ratio, response time, and optical parameters.

Main Methods:

• Numerical simulation of a plasmonic switch composed of gold cross-shaped resonators.
• Integration of germanium-antimony-tellurium (GST) as a tunable phase-change material.
• Analysis of performance under varying temperatures and GST states (amorphous/crystalline).
• Extraction of an equivalent circuit model for validation.
• Evaluation of polarization, incident angle, and geometric parameter effects.

Main Results:

• Achieved a wideband plasmonic switch operating in the near-infrared region.
• Demonstrated tunability by switching GST between amorphous and crystalline states.
• Obtained an optimal extinction ratio of 14 dB and a rapid response time of 46 fs at 1228 nm wavelength.
• Verified numerical results using an equivalent circuit model.
• Assessed the impact of polarization, incident angles, and geometric parameters on device performance.

Conclusions:

• The proposed tunable and wideband plasmonic switch exhibits excellent switching capabilities.
• The device is suitable for integration into optical modulators, logic gates, and optical integrated circuits.
• GST's phase-change properties are effectively leveraged for tunable plasmonic applications.