Spatial Coherence Conversion with Surface Plasmons Using a Three-slit Interferometer

Abstract It has been demonstrated recently that sur-face plasmons can change the state of coherence of light emanating from a Young’s double-slit interfer-ometer. This suggests the possibility of developing a “coherence-converting ” device with a large array of subwavelength holes in a metal plate. We have taken an intermediate approach by considering a three-slit geometry, in which we investigated the effects on the modulation of the spatial coherence when an additional slit is placed between the pair of Young’s slits. Our results show that the amount of modulation (enhance-ment or suppression) can be increased or decreased in the three-slit geometry, compared to the double-slit configuration. This is promising for achieving coher-ence converting optical devices with suitable arrays of subwavelength holes