Polarization-Sensitive Terahertz Bolometer Using Plasmonically-Heated Vanadium-Dioxide Beam.

We present an uncooled high-sensitivity bolometric terahertz detector by incorporating plasmonic absorbers and transducer beams made of phase changing materials. We present a comprehensive design parameter analysis of the bolometer device—from electromagnetic absorption to thermal and mechanical analysis. Our design integrates plasmonic absorber and vanadium dioxide (VO2) beams biased at transition temperature to achieve ultra-high temperature coefficient of resistance. The beams are positioned in proximity to plasmonic hot spots created by radiation absorption. Such integration simultaneously allows spectrum selectivity and tunability in radiation absorption across a wide band in the THz regime as well as high-sensitivity detection by a small-footprint device. The design additionally facilitates simultaneous sensing of intensity and polarization of incident radiation by utilizing polarization-dependent plasmonic field enhancement. We estimate a responsivity over 5 kV·W−1, noise equivalent power (NEP) below 12 pW, and normalized detectivity over 108 cm·Hz1/2·W−1 which are competitive to state-of-the-art THz bolometer designs. [ABSTRACT FROM AUTHOR]