PHOTODETECTION DEVICE

• Main Author: KASAHARA KUMIO
• Format: Patent
• Language: English
• Published: 27.06.1989
• Subjects: BASIC ELECTRIC ELEMENTS; COLORIMETRY; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; RADIATION PYROMETRY; SEMICONDUCTOR DEVICES; TESTING

PURPOSE:To enable high-sensitivity, wide-band photodetection without cooling liquid helium by forming a superconducting ring and Josephson junctions of necessary metal oxide and providing a magnet which applies a specific magnetic field in a prescribed direction and an optical fiber for light incidence. CONSTITUTION:The superconducting ring 6 which form the two Josephson junctions 2 using metal oxide such as YBa2Cu2O7-8, (delta 0.1) is provided on a dielectric substrate 5, and the ring 6 is supplied with a current from the outside through an electrode 7 and also applied with the magnetic field which is (n+1/2) times as intense as a magnetic quantum phi0=2.07X10<-15>Wb (n: integer) by a magnet 8 in a direction perpendicular to a plane forming the ring 6. The superconductive ring which uses this necessary metal oxide having high critical temperature operates at high temperature of >=77K without being cooled with liquid helium, and incident light from the optical fiber 3 is photodetected as the deviation quantity of the two Josephson junctions from the null state of a quantum interference state, thereby obtaining a photodetection element which performs the high-sensitivity, wide-band photodetection without being cooled with the liquid helium.