A study of improving the performance of surface plasmon resonance based biosensors is presented in this book, which is achieved by reducing the noisy effects of optical modes such as Fabry-Pérot modes within the prism of the sensor. We showed that using single or multiple layers of anti-reflection coating on top of the biosensor prism helps the Fabry-Pérot mode propagate out of the prism easily and thus rids the equipment of the noisy effects to a significant extent.