Optical Response of a Cold-Electron Bolometer Array Integrated in a 345-GHz Cross-Slot Antenna
Artikel i vetenskaplig tidskrift, 2011
Two series/parallel arrays of ten cold-electron
bolometers with superconductor–insulator–normal tunnel junctions
were integrated in orthogonal ports of a cross-slot antenna.
To increase the dynamic range of the receiver, all single bolometers
in an array are connected in parallel for the microwave
signal by capacitive coupling. To increase the output response,
bolometers are connected in series for dc bias. With the measured
voltage-to-temperature response of 8.8 μV/mK, absorber
volume of 0.08 μm3, and output noise of about 10 nV/Hz1/2,
we estimated the dark electrical noise equivalent power (NEP)
as NEP = 6∗ 10−18 W/Hz1/2. The optical response down to
NEP = 2∗ 10−17 W/Hz1/2 was measured using a hot/cold load
as a radiation source and a sample temperature down to 100 mK.
The fluctuation sensitivity to the radiation source temperature is
1.3 ∗ 10−4 K/Hz1/2. A dynamic range over 43 dB was measured
using a backward-wave oscillator, a variable polarization grid
attenuator, and cold filters/attenuators.
cold-electron bolometers (CEBs)
superconducting integrated circuits