Time-Averaged Moiré Fringes

λ

0.1

0.2

0.3

n

2

16

32

64

This Demonstration illustrates the formation of time-averaged moiré fringes. The horizontal axis stands for the amplitude of harmonic oscillation

a

; the vertical axis represents the longitudinal coordinate

x

. Stationary moiré grating is visualized at

a=0

. Time-averaged images of the moiré grating are shown at increasing amplitudes of oscillation. The parameter

λ

controls the density of the moiré grating lines. The parameter

n

controls the number of discrete time nodes in a period of the oscillation used to integrate the dynamical process. Double exposure fringes are produced at

n=2

; time-averaged fringes are produced at

n∞

. One can observe the development of time-averaged fringes at increasing

n

.