The field of fiber optic biosensors (FOBSs) is an intensively active area of modern biophotonics technologies because these sensors are potential alternatives to conventional medical methods for diagnostics and monitoring of diseases. Fiber optic biosensors offer a minimally invasive, highly sensitive, and accurate means for measurement and control of various physical and biomedical quantities. Biosensor techniques and devices utilizing minimally invasive FOBSs technology are rapidly finding their way into the mainstream for early disease diagnostics, laser therapy, and in situ optical biosensing and bioimaging.