Patent · US Expired

Photodetecting device

US4578691A · kind A · utility

12Cited by
2References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 14, 1984
Grant dateMar 25, 1986
Priority date
Expiry dateSep 14, 2004

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S505/874

Abstract

A photodetecting device having Josephson junctions, comprises an insulating substrate, a polycrystalline superconductor film formed on the insulating substrate such that Josephson junctions are formed at grain boundaries, the superconductor film having a first region subjected to light illumination, and second and third regions formed contiguously at both sides of the first region such that a width of each of the second and third regions is wider than that of the first region, a bias circuit for supplying a predetermined bias current between the second and third regions, and an output circuit for detecting a change in voltage between the second and third regions, one terminal of said bias circuit and one terminal of said output circuit being commonly grounded, wherein the superconductor film comprises BaPb.sub.1-x Bi.sub.x O.sub.3 (where 0.05.ltoreq.x<0.32) having an I-V characteristic of weak link type under temperature condition less than transition temperature of said BaPb.sub.1-x Bi.sub.x O.sub.3. This simple photodetecting device can detect an optical signal at high speed with high sensitivity.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.