Development of Josephson Junctions and Arrays as Infrared Detectors for an Image Processor.
Abstract
The optical response of Nb-Al0x-Nb Josephson junctions and series arrays of such junctions has been studied in the 1 to 20 micron region of the infrared. Gap suppression on irradiation has been observed, leading to ultra-high sensitivities of order of 100,000 Volt/Watt. Such high responsivities are not possible over an entire wavelength range using conventional technologies. The devices are found to show linear response even at ultra-low intensities of order 200 femtoWatts/device. Attempts have been made to further improve the external quantum efficiency and voltage responsitivity of the devices by using counterelectrodes with lower reflectivities. The high quantum efficiencies (S100) of the devices may be explained by the creation of quasi-particles by the incident photon, and a further increase in quasi-particle number density by interaction with phonons.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 29, 1987
- Accession Number
- ADA176753
Entities
People
- M. Radparvar
- S. Baliga
- S. M. Faris