Surface plasmon resonance biosensor as a tool for the measurement of complex refractive indices.

Optical characterisation of liquids through the measurement of their complex refractive index is critical in environmental monitoring, food industry and medicine. While surface plasmon resonance is widely used for measurement of the real part of the refractive index there have been few studies to date on measurement of complex refractive index with this method. We present a systematic study which highlights the challenges associated with this approach. Instrument design and data analysis techniques are presented together with preliminary experimental results.