Highly sensitive open channel based PCF-SPR sensor for analyte refractive index sensing
Nazrul Islam, Md. Faizul Huq Arif, Mohammad Abu Yousuf, Sayed Asaduzzaman
Abstract
The control of light in photonic crystal fiber (PCF) is a special characteristic that is obtained due to the relations between material and light. In this paper, a surface plasmon resonance (SPR) based PCF sensor is introduced with two open-channel which cover an extensive field of bio-detection applications. Gold (Au) is considered as an effective plasmonic ingredient. The transformation of light through the fiber core is coupled with the gold and stimulates SPR. The proposed PCF-SPR sensor reports the highest wavelength sensitivity (WS) of 7000 nm/RIU (refractive index unit) as well as an amplitude sensitivity (AS) of 593.61 RIU−1. It also acquires an increased sensor resolution of 1.43 × 10−5 RIU and a decent figure of merit (FOM) is 94.97 RIU−1. Additionally, the operating constraints of the sensor such as corresponding air-holes diameter, the pitch, gold layer (Au) thickness and open-channel radius are revised to improve detection performance. The overall measurement is carried out over a broad range of variations in refractive index (RI) from 1.33 to 1.40. The sensor's appreciable performance makes it suitable for bio-sensing applications.