We simulate the field distribution of a fully developed speckle pattern (SP) due to diffusion of laser light from a remote rough surface. We show that, under some circumstances, the phase fluctuation and the logarithm of intensity are linked by Hilbert transform, excluding deep intensity minima. To overcome the problems arising from deep intensity minima., we propose the integration of the SP field over the finite detector area. We compute the autocorrelation function of the SP along the longitudinal axis z as a function of the detector area; we find a rapid increase of the correlation length with the detector area, up to a nearly complete correlation for integration just over a few transversal speckles. We conclude that the Hilbert transform method could open the way to compensation of SP phase errors in interferometric measurements.
Correlation Between Intensity and Phase in Speckle Pattern Interferometry
MARTINI, GIUSEPPE;
2000-01-01
Abstract
We simulate the field distribution of a fully developed speckle pattern (SP) due to diffusion of laser light from a remote rough surface. We show that, under some circumstances, the phase fluctuation and the logarithm of intensity are linked by Hilbert transform, excluding deep intensity minima. To overcome the problems arising from deep intensity minima., we propose the integration of the SP field over the finite detector area. We compute the autocorrelation function of the SP along the longitudinal axis z as a function of the detector area; we find a rapid increase of the correlation length with the detector area, up to a nearly complete correlation for integration just over a few transversal speckles. We conclude that the Hilbert transform method could open the way to compensation of SP phase errors in interferometric measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
