A wafer-level camera approach based on the Gabor superlens

Abstract

The integration of camera modules in portable devices is increasing rapidly. At the same time, their size is shrinking due to the need for mobility and reduction of costs. For this purpose, an ultra-compact imaging system has been realized, which adapts the multichannel imaging principle of superposition compound eyes known from nocturnal insects. The application forms an erect image by using a pair of microlens arrays with slightly different pitches, which is also known as superlens. The microoptical design was optimized by using numerical ray tracing methods with respect to the capabilities of state-of-the-art microoptics fabrication technology. Additional aperture/diaphragm layers and a field lens array had to be introduced in order to avoid channel cross talk. As a result, the optical performance is comparable to that of miniaturized conventional lens modules. However, the fabrication of the microoptical Gabor superlens is kept simple and scalable in terms of wafer-level technology due to the use of microlens arrays with low sag heights and small microlens diameters.