We simulate the field distribution of a fully developed speckle pattern (SP) due to diffusion of laser light from a remote surface. We show that the phase fluctuation and the logarithm of intensity fluctuation are linked by Hilbert transform, excluding points where the field vanishes. To overcome the problems arising from zero field points, 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 diffuser and the detector areas; 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. The Hilbert-transform method could open the way to compensation of SP phase errors in interferometric measurements.
Correlation between intensity and phase in Spackle-Pattern Interferometry
MARTINI, GIUSEPPE;DONATI, SILVANO
1999-01-01
Abstract
We simulate the field distribution of a fully developed speckle pattern (SP) due to diffusion of laser light from a remote surface. We show that the phase fluctuation and the logarithm of intensity fluctuation are linked by Hilbert transform, excluding points where the field vanishes. To overcome the problems arising from zero field points, 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 diffuser and the detector areas; 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. 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.
