TiN-GST-TiN all-optical reflection modulator for the 2 µm wave band reaching 85% efficiency.

In this study, we present an all-optical reflection modulator for the 2 µm communication band exploiting a nanogear-array metasurface and phase-change-material (GST). The reflectance of the structure can be manipulated by altering the phase of GST by employing optical stimuli, and this paper provides details on the optical and opto-thermal modeling techniques of GST. A numerical investigation reveals that the metastructure exhibits a conspicuous changeover from ∼99 absorption to very poor interaction with the operating light depending on the switching states of the GST, ending up with 85% modulation depth and only 0.

Structurally tunable gear-shaped plasmonic sensor.

We present a gear-shaped plasmonic nano-structure with structural tunability and high RI sensitivity. New tunable geometric parameters of the gear-tooth give further flexibility for design. By using FDTD method, the reflection spectrum of the structure is theoretically analyzed with analyte RI in the range of 1.