EXPERIMENTAL REALIZATION OF A SEMICONDUCTOR PHOTON NUMBER AMPLIFIER AND A QUANTUM OPTICAL TAP

Two configurations involving high quantum efficiency photodetectors an d light emitting diodes have been investigated. A light beam was detec ted with a photodetector and its photocurrent was used to measure the incoming beam. Simultaneously, the photocurrent was used, with and wit hout amplification, to regenerate the absorbed beam. With these scheme s photon number amplification, duplication, and information tapping wi thout introducing any significant noise to the downstream propagating beam could be experimentally realized.