We present the experimental results and a bolometer model of the voltage-biased superconducting bolometer on the lowstress silicon nitride (Si3N4) membrane, developed in collaboration between the Max-Planck-Institut fur Radioastronomie(MPIfR), Bonn and the Institute for Photonic Technology (IPHT), Jena, Germany. The superconducting thermistor, de-posited on the low stress silicon nitride membrane, is a bilayer of gold-palladium and molybdenum and is designed for atransition temperature of 450 mK. Bolometers for the 1.2 mm atmospheric window were designed, built and tested. Thethermal conductance of the bolometer is tuned by structuring the silicon nitride membrane into spider-like geometries.The incident radiation is absorbed by crossed dipoles made from gold-palladium alloy with a surface resistance of 10Ω/square. Using the COSMOS finite element analysis package, the thermal conductance is obtained for the bolometers ofdifferent geometries. FEA simulations showed that the deposition of a gold ring around the absorbing area could increasethe sensitivity of the bolometer. Therefore, a gold ring is deposited around the center absorbing patch of the silicon nitridemembrane. For the bolometer with a gold ring, the measured NEP is 1.7 x 10 ~(–16)W/√Hz and the time constant is in therange between 1.4 and 2 ms.
展开▼
