Superconducting tunnel junctions as photon counting detectors in the infrared to the ultraviolet

Photon counting experiments with Ta/Al superconducting tunnel junctions are presented. Single photon detection is demonstrated in the wavelength range /spl lambda/=200-2000 nn with a resolving power /spl lambda///spl Delta//spl lambda/=22-4. The response of the detector shows good linearity with photon energy.