An improved refractive index sensor based on genetic optimization of plasmon waveguide resonance.

Plasmon waveguide resonance (PWR) sensors are particularly useful for biosensing due to their unique ability to perform sensing with two different polarizations. In this paper we report a comprehensive performance comparison between the surface plasmon resonance (SPR) sensor and the PWR sensor in terms of the sensitivity and the refractive index resolution. Both sensors were optimized using a genetic algorithm to acquire their best performance for bulk sensing applications. The experimental results show that the PWR sensor has a refractive index resolution of 5 × 10(-7) RIU which is 6 times smaller than that of the optimized SPR sensor. The TE polarization in the PWR sensor has a resolution of 1.4 × 10(-6) RIU which is smaller than the SPR sensor. The polarization diversity in the PWR sensor is another advantage which can be used to improve the measurement reliability.