Development of fiber optical sensor with resonator

An optical fiber sensor based on evanescent wave sensing and excitation light resonance using a pair of optical reflectors adjacent to two ends of the optical fiber is presented. Excitation light is coupled into the fiber optical sensor through a hole in the first reflector. The excitation light starts to resonate between the reflectors, and results in the amplification of the fluorescent signal, which is generated by the excitation of the analyte binding to the surface of the active fiber sensing area. This device was successfully demonstrated in achieving over 600% amplification in the output signal. This design provides a simple and efficient method in improving the S/N and the sensitivity of the optical fiber evanescent wave sensor over the traditional approach.