Stark-Effect Intersubband Polaritonic Metasurfaces for free-space infrared modulation

TransWave Photonics, in collaboration with Sandia National Labs, proposes to further develop a fast, efficient infrared free-space optical modulator based on voltage-controlled optical metasurfaces consisting of metallic nano-resonators loaded with semiconductor multiple-quantum-wells. Electronic transitions within quantum wells are engineered to support large quantum confined Stark effect with switching speed at picosecond timescales. The nano-resonators enable coupling to intersubband transitions from free-space, typically prohibitive due to selection rules for optical absorption. The proposed design framework is applicable for all relevant mid-infrared wavelengths, enabling compatibility with the full spectrum of mid-infrared lasers. In Phase I, TransWave investigated and presented metasurface modulator design architectures suitable for reaching 40 GHz signal bandwidth, with low insertion loss and high modulation depth while operating at LWIR wavelengths. In Phase II, TransWave seeks to further design, manufacture, and characterize metasurface modulator prototypes suitable for free-space optical communications, targeting deployment and integration into existing DoN testbeds.