A novel gold-coated multimode fiber sensor

A novel optical-fiber sensor is proposed for use in chemical analysis. The sensor probe is made of a gold-coated multimode optical fiber, configured to exhibit surface plasmon resonance (SPR) when immersed in a wet environment. The proposed detection strategy comprises measurement of the image pattern irradiated by the fiber under monochromatic illumination. A theoretical model is proposed to determine device performance. From computer simulations, it is shown that the proposed configuration and detection strategy allows reaching a 30-fold enhancement in sensitivity relative to that obtained in previous SPR-based versions of the device. Index Terms--Chemical sensor, fiber sensor, gold, SPR, surface plasmon.