Highly Reliable Flexible Active Optical Links

We present a process to embed commercially available optical material layers into a flexible foil. Patterning of the embedded layers results in highly transparent low loss flexible waveguides. Bending of the foil down to a bending radius of 5 mm causes no additional optical propagation losses. Vertical-cavity surface-emitting laser diodes (VCSELs) and photodiodes are thinned down to 20 mu m and embedded inside the cladding layer of the waveguides. They are optically coupled with the use of embedded micro-mirrors. The result is a thin foil of 150-mu m thickness with embedded active optical low-loss links. Accelerated aging tests prove the reliability of the embedded optical links exposed to humidity and temperature cycling.