Standard and non-standard metarefraction with confocal lenslet arrays

A recent paper demonstrated that two lenslet arrays with focal lengths f1f1 and f2f2, separated by f1+f2f1+f2, change the direction of transmitted light rays approximately like the interface between isotropic media with refractive indices n1n1 and n2n2, where n1/n2=-f1/f2n1/n2=-f1/f2 [J. Courtial, New J. Phys. 10 (2008) 083033]. This is true if light passes through corresponding lenslets, that is lenslets that share an optical axis. Light can also pass through different combinations of non-corresponding lenslets. Such light can be either absorbed or allowed to form “ghost images”; either way, it leads to a limitation of the field of view of confocal lenslet arrays. This paper describes, qualitatively and quantitatively, a number of such field-of-view limitations.