The coupling efficiency between laser diode arrays or OEIC components and single-mode fiber ribbons drops rapidly with increasing misalignment tolerance. There are trade-offs between the allowed minimum coupled power and the cost of establishing the required alignment. We demonstrate how tapered polymer waveguides may be used to match the laser mode to the fiber mode, resulting in a module with decreased alignment requirements for a given coupling efficiency. Waveguides with tapered mode profiles have been constructed using photobleaching of a guest/host dye/polymer system. Amoco 4212 polyimide doped with DCM dye was chosen as the waveguide material due to its good thermal stability, and its simple processing which allows multilayer waveguides to be readily fabricated. In particular, waveguides which simultaneously taper the mode both laterally and vertically have been designed. This waveguide system is compatible with assembly of the laser and waveguide components into a module by flip-chip soldering. Our solder self-alignment technique achieves accurate alignment of touching chips through an understanding of the dynamics during bonding.

Date Published: 22 November 1996
PDF: 11 pages
Proc. SPIE 2844, Photonics and Radio Frequency, (22 November 1996); doi: 10.1117/12.258989

Published in SPIE Proceedings Vol. 2844:
Photonics and Radio Frequency
Brian M. Hendrickson, Editor(s)