An Intensity-Modulated Optical Fibre Displacement Sensor with Convex Reflector

A novel intensity-modulated optical fibre displacement sensor with convex reflector technology is described. A common form of the intensity-modulated optical fibre sensor performs its measurement by making use of a pair of straight optical fibres with a plane reflector. The reflected optical signal intensity changes as a function of change in displacement. This paper describes an alternative sensing structure with a convex reflector instead of a plane reflector and demonstrates the derivations of geometric and Gaussian mathematical models. The blind region or non-sensitive region is minimized when the plane reflector is replaced by a convex reflector. Such type of optical sensor can be used where space required for the measurement is the major limitation. Since the intensity stabilization of light emitting diode (LED) is the prime necessity of intensity modulated optical fibre sensors, the instrumentation for intensity stability of LED is developed.