Plastic planar-integrated free-space optical interconnector

The planar integration of free-space optical (PIFSO) systems on poly(methyl methacrylate) (PMMA) substrates was demonstrated using an example of a fiber-to-free-space-to-fiber interconnecter module. This plastic module was designed to accommodate standard mechanically-transferable- (MT-) connected fiber cables and contained a set of two nested refractive imaging lenses, one of which was used as an off-axis lens. In our experiment, an average coupling efficiency of -4.4 dB and a crosstalk suppression larger than 33 dB were measured. The performance, fabrication tolerances, and operation conditions of this interconnecter module as well as the general benefits of plastic materials for the PIFSO systems were discussed.