Highly amplitude-sensitive photonic-crystal-fiber-based plasmonic sensor

Simple structure, quick response, and highly sensitive miniaturized sensors are highly desirable for the broad range of sensing applications. In this work, we numerically investigated a highly sensitive photonic-crystalfiber (PCF)-based plasmonic sensor for refractive index sensing. We consider gold as the plasmonic material, which is used outside the fiber structure to exhibit the plasmonic phenomena and to help detect the surrounding medium refractive index. The proposed PCF is designed to enable the evanescent field to interact with an external sensing medium leading to a highly sensitive response. The sensor performance has been investigated by wavelength and amplitude interrogation methods. The proposed sensor exhibits the maximum amplitude sensitivity of 2,843 RIU-1 with the sensor resolution of 3.5 x 10(-6) RIU, which is the highest among the reported PCF SPR sensors, to the best of our knowledge. It also shows wavelength sensitivity of 18,000 nm/RIU and sensor resolution of 5.6 x 10(-6) RIU. The figure of merit of the proposed sensor is about 400. The sensor response also allows us to detect the refractive index variation in the range of 1.33 to 1.41. Such promising results and broad sensing range ensure that the proposed sensor will be a suitable candidate for biological analytes and biochemical and organic chemical detections. (C) 2018 Optical Society of America.