Long-range surface plasmon waveguides, and their application to various transducer architectures for amplitude- or
phase-sensitive biosensing, are discussed. Straight and Y-junction waveguides are used for direct intensity-based
detection, whereas Bragg gratings and single-, dual- and triple-output Mach Zehnder interferometers are used for phasebased
detection. In either case, multiple-output biosensors which provide means for referencing are very useful to
eliminate common perturbations and drift. Application of the biosensors to disease detection in complex fluids is
discussed. Application to biomolecular interaction analysis and kinetics extraction is also discussed.
Long-range surface plasmon-polariton (LRSPP) waveguide structures fabricated of gold stripes (5 μm wide and 35
nm thick) embedded in CYTOP were characterized. TM polarized 1310 nm light emerging from a polarisationmaintaining
optical fibre was injected into the structures via butt-coupling and the output light was measured so that
the loss could be calculated. Cutback measurements were carried out on straight waveguides so as to determine their
attenuation as well as the butt-coupling loss per facet. Various other passive elements were also characterized. The
results were compared with theoretical expectations and errors are surmised to be caused by fabrication
imperfections. Thermo-optic modulation measurements were also carried out on straight waveguides. These
elements are of interest for biosensors, where propagation through an aqueous solution (having an index of
refraction very close to that of Cytop) is necessary.