Chemical sensing with gold coated optical fibers

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 on 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 attaining a 30-fold enhancement in sensitivity relative to that obtained in previous SPR-based versions of the device.