Thermally Reconfigurable Antennas & ENZ Media

Thermally Reconfigurable Antennas

We are developing optical devices capable of real-time reconfiguration using epsilon-near-zero (ENZ) substrates. By depositing nanophotonic antennas onto ENZ films (e.g., doped indium oxide, cadmium oxide), we leverage field confinement near the zero-index transition to achieve resonance shifts and radiation pattern control.

Tunability via ENZ Materials

ENZ Amplification of Thermo-Optic Effects ― By coupling dielectric resonators to ENZ substrates, we have demonstrated 5 nm/V tuning, a significant enhancement over conventional silicon antennas, while maintaining high Q-factors (>150). This is achieved without phase-change materials, relying instead on the field concentration properties of ENZ materials.

Thermally Reconfigurable Meta-Lenses ― We have developed binary-phase CdO pillar arrays that allow for dynamic reconfiguration of focal length (from 50 to 120 μm) using 10 milliwatts of Joule heating.

High Efficiency ― The field enhancement near ENZ transitions enables optical reconfiguration with high efficiency, suitable for low-power applications.

Future Outlook

Our work contributes to the development of active optical elements that can sense and adapt. Potential applications include adaptive infrared cameras, programmable thermal emitters, and dynamic wavefront shapers for free-space communication.

Suggested reading

• Publication: High-Q, Size-Independent, and Reconfigurable Optical Antennas Embedded in Zero-Index Cavities (ACS Nano 2025)
• Publication: Thermally Reconfigurable Meta-Optics
• Publication: Ultrawide Thermal-Free-Carrier Tuning of Dielectric Antennas Coupled to ENZ Substrates