Quantum Optical Measurements Research Articles

Detection of optical squeezing and photon statistics in polaritons

Methods are proposed and theoretically analysed for the detection of optical squeezing and non-poissonian photon statistics in exciton and phonon-polaritons. These quantum-optical effects were theoretically predicted by us. The novel idea here is to probe the evanescent portion of the bulk polariton at total internal reflection on the crystal surface, to determine the photocount statistics of the bulk wave. The estimated experimental sensitivity is comparable to that used in analogous quantum optical measurements.

Photoemission studies on metals using picosecond ultraviolet laser pulses

We report the quantum efficiency of various metals irradiated by 266-nm, 4.66-eV laser pulses of 10-ps duration. The highest quantum efficiency obtained is 7.25×10−4 with samarium photocathodes. Current densities exceeding 66 and 21 kA/cm2 have been obtained from an area of 0.05 and 7 mm2, respectively. The maximum currents and current densities obtainable in these experiments are limited by the space charge. For surface fields exceeding 5×107 V/m on gold, the efficiency increases linearly with the field for the values investigated. Based on the quantum efficiency and optical damage threshold measurements, current densities exceeding 100 kA/cm2 seem feasible without damaging the photocathode.