Terahertz Direct Detection in ${\hbox {YBa}}_{2}{\hbox {Cu}}_{3}{\hbox {O}}_{7}$ Microbolometers

A high sensitivity broadband terahertz direct detector based on YBa₂Cu₃O₇ high-Tc superconductor microbolometers is presented. At 77 K, the responsivity of the spiral antenna-integrated microbolometers (1.5 μm ×1.5 μm) is 190 V/W, referenced to the input of the silicon substrate lens, across the frequency range of 330 GHz-1.63 THz in a single device. The response time is approximately 300 ps. Using a room temperature readout, we measure an optical noise equivalent power (NEP) of 20 pW/Hz^0.5 (readout noise limited) for modulation frequencies ranging from 500 Hz to 100 kHz.