Two different approaches for ultra flat image acquisition sensors on the basis of artificial compound eyes are examined. In apposition optics the image reconstruction is based on moiré-or static sampling while the superposition eye approach produces an overall image. Both types of sensors are compared with respect to theoretical limitations of resolution, sensitivity and system thickness. Explicit design rules are given. A paraxial 3x3 matrix formalism is used to describe the arrangement of three microlens arrays with different pitches to find first order parameters of artificial superposition eyes. The model is validated by analysis of the system with raytracing software. Measurements of focal length of anamorphic reflow lenses, which are key components of the superposition approach, under oblique incidence are performed. For the second approach, the artificial apposition eye, a first demonstrator system is presented. The monolithic device consists of a UV-replicated reflow microlens array on a thin silica-substrate with a pinhole array in a metal layer on the backside. The pitch of the pinholes differs from the lens array pitch to enable an individual viewing angle for each channel. Imaged test patterns are presented and measurements of the angular sensitivity function are compared to calculations using commercial raytracing software.

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The demand for precise micro-optical elements and subsystems is increasing drastically, influenced mainly by the exploding information and communications markets. For many applications, technologies capable of high-volume production of these elements are needed. Favored methods are replication technologies such as injection molding, hot embossing, or UV molding. The challenge for materials scientists is to synthesize materials that can be formed into micro-optical structures and that can resist extreme environmental conditions during operation and stocking (e.g., temperature changes from −45°C to +125°C).

A replication technique allowing for the wafer scale integration ofmicrooptical elements is presented and illustrated by various examples. The technique is based on polymer UV reaction moulding using a modified contact mask aligner where mask and wafer are replaced by the replication tool and an arbitrary substrate (on top ofwhich the microstructures are to be replicated), respectively. The technology takes advantage ofthe high precision and adjustment accuracy of photolithography equipment. The replication masters are nickel shims, etched Silicon wafers or uv-transparent fused silica tools. The latter ones allow for replication on opaque substrates. Additionally, polymer elements with unique properties can be obtained by the combination ofreplication and resist technology using partially transparent replication tools. Wafer scale hybrid integration of micro-optical subsystems is accomplished by replication of polymer elements like lenses, lens arrays, micro prisms etc. onto semiconductor wafers containing detectors or VCSELs, or, by combining micro-optical elements on both sides of a glass wafer. The use ofthin layers ofuv cured (crosslinked) polymers on inorganic substrates results in good thermal and mechanical stability compared to all-polymer devices.

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