Intensity correlations in metal films with periodic-on-average random nanohole arrays

• Plasmonic nanohole arrays in a periodic-on-average random template are studied.
• Intensity distributions show lasting correlations across disorder strengths.
• Strength of correlations is related to the intensity-pinning to the nanoholes.

We report detailed numerical studies based on three-dimensional finite-difference time domain computations of the intensity–intensity correlations in deliberately randomized, periodic-on-average systems. Correlation analyses are carried out in plasmonic thin films with nanohole arrays as a function of strength of disorder. We find that the intensity at certain uncharacteristic wavelengths remains strongly correlated with that in the periodic system, and these wavelengths do not match the global maxima of the periodic transmission spectrum. The study indicates that the strength of correlations is related to the pinning of the intensity to the holes. Since the intensity pinning is special characteristic of metals, the effect is only applicable in plasmonic systems.