Advances in polymer integrated optics

We report on advances in polymeric waveguide technologies developed worldwide for the telecom and datacom markets, and we describe in detail one such technology developed at AlliedSignal. Optical polymers are versatile materials that can be readily formed into planar single-mode, multimode, and microoptical waveguide structures ranging in dimensions from under a micrometer to several hundred micrometers. These materials can be thermoplastics, thermosets, or photopolymers, and the starting formulations are typically either polymers or oligomers in solution or liquid monomers. Transmission losses in polymers can be minimized, typically by halogenation, with state-of-the-art loss values being about 0.01 dB/cm at 840 nm and about 0.1 dB/cm at 1550 nm. A number of polymers have been shown to exhibit excellent environmental stability and have demonstrated capability in a variety of demanding applications. Waveguides can be formed by direct photolithography, reactive ion etching, laser ablation, molding, or embossing. Well-developed adhesion schemes permit the use of polymers on a wide range of rigid and flexible substrates. Integrated optical devices fabricated to date include numerous passive and active elements that achieve a variety of coupling, routing, filtering, and switching functions.