Light Detection by Superconducting Weak Link Fabricated with High-Critical-Temperature Oxide-Superconductor Film

The light-induced changes in the current-voltage characteristics are studied for a superconducting weak link fabricated with a polycrystalline YBa2Cu3O7-δ film. The maximum superconducting current decreases by exposure to light at temperatures up to 77 K. The sensitivity of the light detection is enhanced by the use of a photoconductive semiconductor film on the surface of the weak link.