VOLTAGE RESPONSES TO OPTICAL PULSES OF UNBIASED NORMAL AND SUPERCONDUCTING SAMPLES

The direct transformation of the energy of an incident high-energy pho ton into a measurable potential difference within an absorbing metal i s investigated. Experimental evidence is presented that the effect ari ses from the inherent energy dependence of the electronic density of s tates, rather than from a simple temperature excursion. The similariti es between the results on Al and YBa2Cu3O7 samples indicate that the e ffect is universal in nature. We assert it may be used as the basis of a fast, energy resolving, individual photon detector for the ultravio let radiation and x-rays. (C) 1997 American Institute of Physics.