The characteristic polynomials associated with the algorithms used in
digital phase detection are used to investigate the effects of additiv
e noise on phase measurements. First, it is shown that a loss factor e
ta can be associated with any algorithm. This parameter describes the
influence of the algorithm on the global signal-to-noise ratio (SNR).
Second, the Variance of the phase error is shown to depend mainly on t
he global SNR. The amplitude of a modulation of this variance at twice
the signal frequency depends on a single parameter beta. The material
presented here extends previously published results, and as many as 1
9 algorithms are analyzed. (C) 1997 Optical Society of America