ADDED NOISE IN HOMODYNE MEASUREMENT OF FIELD OBSERVABLES

Homodyne tomography provides a way for measuring generic field operato rs. Here we analyze the determination of the most relevant quantities: intensity, field, amplitude and phase, We show that tomographic measu rements are affected by additional noise in comparison with the direct detection of each observable by itself, The case of coherent states h as been analyzed in detail and earlier estimations of tomographic prec ision are critically discussed. (C) 1997 Elsevier Science B.V.