Exploiting incoherent synthetic apertures in integral imaging for optical super-resolution

Integral imaging (InIm) working with a pixelated device (e.g., a display panel) and a microlens array (MLA) suffers from low spatial resolution because of a significant trade-off between the spatial and angular resolution. The system bandwidth is presumed to be limited by the Nyquist frequency set by the pixel pitch. This study demonstrates that InIm intrinsically works in an incoherent synthetic aperture (ISA) manner with unexploited resolution capabilities. The sampling shifts between lenslets can be controlled and utilized to construct “computational galvos” to introduce varying aliasing; as a result, the Nyquist frequency is broken for optical super-resolution (SR). In particular, an InIm system can be configured for an N-fold oversampling rate with N lenslets. Furthermore, in an InIm display, the fill factor of a pixel’s emitting area is always lower than 100%, so the bandwidth limit set by the pixel shape, i.e., two times the Nyquist frequency, is loosened. An InIm display prototype was built with an oversampling rate of four and a pixel fill factor of 75%. In the experiment, the proposed SR method achieved a 2.12 times resolution without dynamic devices or time-multiplexing.