Highly Sensitive Optical Detector Using Superconducting Oxide BaPb0.7Bi0.3O3 (BPB)

Abstract
Highly sensitive optical detectors have been fabricated by using superconducting BaPb0.7Bi0.3O3 (BPB) thin films. Optical signals create quasi-particles and induce energy gap changes which can be detected by Boundary Josephson Junctions (BJJs) in the films. The sensitivity is 104 V/W in the 1.0∼10 µm wavelength range and they can respond up to 500 MHz. This device is useful as a detector in an optical communication system or an infrared spectrometer.