Polymer waveguide output couplers

Waveguide output couplers play an important role in current investigations in optical interconnections. With the emergence of optical polymers, waveguides may now be fabricated easily and accurately on electronic circuits to form optoelectronic integrated circuits. In this thesis, planar waveguide output couplers fabricated in Norland Optical Adhesive (NOA) #81 and AMOCO Ultradel 9020D Polyimide polymers are investigated. Two types of output couplers are investigated: rectangular relief gratings and binary blazed gratings. Design theory of the couplers is based on the perturbation approach. Coupling of light from waveguide propagation modes to output radiation modes is described by coupled mode theory and the transmission line approximation of the perturbed area (grating structure). Using these concepts, gratings can be accurately designed to output a minimum number of modes at desired output angles. These basic design theories are extended to approximate blazed grating characteristics in a duty-cycle modulated rectangular grating. Both rectangular and binary blazed grating waveguide couplers are designed using these theories. Rectangular relief grating couplers are fabricated and evaluated for structural and beam accuracy, and output efficiency. Applications for these couplers include data bus and clock distribution system interfaces requiring coupling to out-of-plane detectors.