Steerable plasmonic nanoantennas: active steering of radiation patterns using phase change materials

Area of Science:

• Plasmonics and Nanophotonics
• Metamaterials and Nanostructures
• Antenna Engineering

Background:

• Traditional nanoantennas often have fixed radiation patterns.
• Active control over radiation patterns is crucial for advanced photonic devices.
• Vanadium dioxide (VO2) offers tunable optical properties based on phase transitions.

Purpose of the Study:

• To introduce novel steerable nanoantennas (SNs) capable of active radiation pattern control.
• To investigate the steering capabilities of SNs composed of Yagi-Uda nanoantennas and VO2 thin films.
• To explore potential applications in on-chip optical communication and sensing.

Main Methods:

• Fabrication of complex nanoantenna structures by integrating Yagi-Uda nanoantennas with VO2 thin films.
• Utilizing the semiconductor-to-metallic phase transition of VO2 to tune antenna properties.
• Experimental and/or simulation-based characterization of radiation patterns under varying VO2 states.

Main Results:

• Demonstrated active steering of radiation patterns by dynamically changing the phase of VO2 films.
• Achieved a maximum steering angle of 90° in the plane for a two-element SN.
• Showcased a four-element SN enabling full 360° active steering with 12 distinct steerable directions.

Conclusions:

• The proposed steerable nanoantennas offer significant advancements in radiation pattern control.
• These SNs exhibit enhanced directivity compared to previous designs.
• Potential applications include tunable on-chip plasmonic interconnects, networks on chip, and selective fluorophore excitation.