Low Cost Single Mode Waveguide Fabrication Allowing Passive Fiber Coupling using LIGA and UV flood exposure

A process of UV-induced fabrication of single mode waveguides in a polymer microoptical bench has been realized that offers the unique feature of an inexpensive microstructure replication process for mass fabrication. Instead of using common mask techniques for the realization of the stripe waveguides, a “Self-masking” technique of the polymer by embossing a microoptical bench and a following UV-flood-exposure is used. The mould insert, which is necessary for the replication process was made by the LIGA-technique. The fabrication of the micooptical bench and the waveguides in the same process step assures very good alignment accuracy and guarantees a low cost passive fiber-chip coupling and assembly. The photoinduced chemical reactions of different homoand copolymers of methylmethacrylate under different environmental condition have been investigated. It was shown that depending on the environmental conditions during photoinduced waveguide generation, the physical and chemical properties of the waveguides can be adjusted in a wide range. The process allows the realization of devices for application in telecommunication and sensor technology.