Direct Probing by Laser Scanning of the Current Distribution and Inhomogeneity of Josephson Junctions

Abstract

A laser-scanning technique capable of probing the local current density in Josephson junctions has been used to study the current distribution and inhomogeneity of both high-and poor-quality junctions. Results from a high-quality tunnel junction are in good qualitative agreement with theory. The technique is also shown to be useful to study superconduting-normal-superconducting structures and bridge-type weak links.