Intrinsic Fabry-Perot Interferometer with a Micrometric Tip for Biomedical Applications

This paper presents a novel intrinsic fiber optic Fabry-Perot (FP) structure with a micrometric diameter tip. With the FP cavity inside the fiber, the change in optical path length distance (OPD) caused by the environment can be demodulated. With such a tiny protrusion, the sensor can be inserted into micron size cells for intracellular measurements. This label-free detection method is very useful in biological areas such as DNA hybridization detection. It provides a valuable tool for intracellular studies that have applications ranging from medicine to national security. In addition, the fabrication is simple including only cleaving, splicing, and etching. The signal is stable with high visibility. Last but not the least, the structure shows great promise for reduction to nanometric size. Once this goal is achieved, the sensor can be inserted into most cells with minimal invasiveness.