Abstract: The study offers to perform a differential transformation of optic signals directly in the measuring zone by developing the conic structure of luminous flux and dividing it into two fluxes (each of which is processed in a separate measuring channel) to improve metrological characteristics of fiber-optic sensors based on changing the intensity of luminous flux under the influence of measured physical quantity. The independence of two measuring channels and reduction of linear error are provided in a constructive way. The article gives the examples of structural implementation of differential fiber-optic sensors.