Die Spiegeloptik des Flußkrebsauges

Summary In the superposition eye of the crayfish (Astacus leptodactylus), images are formed by radial plane mirrors arranged in an orthogonal pattern. The optical structure of the crayfish eye can be described as a family of virtual reflecting cone envelopes concentric around each direction in space. There exist two reflection mechanisms: total internal reflection at the sides of the crystalline cones and reflection by multilayer mirrors attached to the distal parts of the cones. Image-forming rays have to be reflected twice in the general case, and once in the case of perpendicular position of the plane of incidence and the mirror plane. For rays incident at small angles to the ommatidial axis, this condition is almost satisfied due to a particular axial variation of the refractive index of the crystalline cone, and for rays incident at large angles, due to the spectral reflecting properties of the multilayer reflector.

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Dissertation der Universität Stuttgart

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Dem Betreuer der Arbeit, Prof. Dr. P. Kunze, danke ich für wertvolle Diskussionen, Frl. M. Gonnert für unermüdliche technische Hilfe und Dipl. Ing. W. Jaschinski für das Nachprüfen von Gleichungen.