Synthesis of intensity patterns in few-mode optical fibers

Interference of selected modes in a fiber supporting few lower-order modes and the resulting intensity patterns are examined. It is shown that by properly choosing the amplitude, phase, and order of the interfering modes, intensity patterns with one or more lobes can be synthesized which exhibit rotational or oscillatory behavior in response to an external disturbance. Excitation of the modes required to generate such intensity patterns is discussed. Sensor application is addressed. An example describing the use of a dual-mode fiber as strain sensor is given