Three bipods slicer prototype: tests and finite element calculations

For integral field spectroscopy R&D activities in progress at LAM, and particularly in relation with SNAP - SuperNova/Acceleration Probe - spectrograph, LAM has an on-going program to qualify Image Slicers for space instrumentation. In this context, an optomechanical concept of an image slicer supported by three bipods has been designed, realized and tested at the laboratory. This paper presents the mechanical design of the invar mount equipped with three bipods and supporting an assembly of 60 thin zerodur slices tied together thanks to optical contact. We document the design improvement made from last blades flexures prototype and we describe all the tests conducted on this new prototype: optical contact tests, vibration tests and thermal cycles. Thanks to a detailed FEM analysis on this three bipods concept, we correlate simulations with tests.