Tunable plasmonic crystal

摘要

A tunable plasmonic crystal comprises several periods in a two-dimensional electron or hole gas plasmonic medium that is both extremely subwavelength (˜λ/100) and tunable through the application of voltages to metal electrodes. Tuning of the plasmonic crystal band edges can be realized in materials such as semiconductors and graphene to actively control the plasmonic crystal dispersion in the terahertz and infrared spectral regions. The tunable plasmonic crystal provides a useful degree of freedom for applications in slow light devices, voltage-tunable waveguides, filters, ultra-sensitive direct and heterodyne THz detectors, and THz oscillators.

主权项

1. A tunable plasmonic crystal, comprising:
a layer providing a two-dimensional electron gas (2DEG) or a two-dimensional hole gas (2DHG), wherein the layer is formed at a semiconductor heterojunction comprising InGaAs/InAlAs, GaN/AlGaN, or GaSb/InAs; a periodic gate comprising at least two parallel finger electrodes disposed on the 2DEG or 2DHG layer; means for applying a gate voltage to the periodic gate to modulate the electron density in the 2DEG layer; or the hole density in the 2DHG layer, thereby producing a spatially periodic plasmon structure having a unit cell; and means to couple incident electromagnetic radiation into the 2DEG or 2DHG layer; wherein the spatially periodic plasmon structure produces a plasmonic band structure when interacting with the incident electromagnetic radiation.