Guru Naik1
Rice University1
Emerging meta-devices need novel optical materials, both metals and dielectrics, for high performance, flexibility, and large-scale integration. Novel metallic materials or plasmonic materials such as transparent conducting oxides and transition metal nitrides have significantly expanded the scope of nanophotonics in the past. Further improvements are required in dielectrics and tunable dielectrics. Here, I will describe how super-Mossian dielectrics enable high performance and quantum materials enable MHz-fast ultralow-power tunability.<br/>Super-Mossian dielectrics are very high index dielectrics that significantly beat the predictions of Moss’ rule. The commonly-known form of Moss’ rule states that the fourth power of the refractive index of a dielectric inversely scales with its direct bandgap or absorption edge. Thus, the refractive index of dielectrics has an upper limit for a given operating wavelength. However, there are certain materials with special energy band features that can significantly beat Moss’ predictions. Here, I will describe how to identify such super-Mossian dielectrics. Also, I will show high-Q dielectric resonances enabled by one such outstanding super-Mossian dielectric, iron pyrite.<br/>While a high refractive index is needed for high-quality factor resonators, tunable optical properties are required for reconfigurable and non-linear devices. Low-power tunability is desired in many such devices because of their applications on mobile platforms. Here, I will show how quantum materials offer a paradigm shift in optical tunability. I will describe ultralow-power MHz-fast optical tunability in 1T-TaS<sub>2</sub>, a charge-ordered material at room temperature. Finally, I will demonstrate tunable and color-changing metasurfaces built on 1T-TaS<sub>2</sub>.