Special features of structural design for a fiber-optic microdisplacement transducer

In this paper, we describe the design of a fiber-optic pressure sensor and the principle of operation. The principle of operation of fiber-optic pressure sensors is as follows. From the radiation source, the light flux along the supply optical fibers is directed to the side of the membrane at an angle, the value of which is selected from the condition of ensuring the maximum sensitivity of the conversion and the depth of modulation of the optical signal. Under the influence of controlled pressure, the membrane deflects, and in the central part the gap between the membrane and the bevelled ends of the optical fibers will be less than the initial value X0. As a result, the reflectivity for electromagnetic waves in the region of the chamfered ends of the optical fibers changes, and accordingly the intensity of the light flux reflected at an angle from the given region, which carries information about the measured pressure and arrives along the diverting optical fibers to the radiation receiver, changes. The optical system of a fiber-optic pressure sensor is calculated, which consists in determining a number of design parameters for a fiber-optic micro-displacement transducer. Mathematical modeling in the MathCAD environment was carried out. Based on the results of mathematical modeling, a new design solution has been proposed for a fiber-optic micro-displacement transducer, in which the incoming and outgoing optical fibers are cut off and located at a calculated angle. The function of converting a fiber-optic micro-displacement transducer is defined. The selected parameters ensure the fulfillment of the conditions for reducing the temperature and dynamic errors, increasing the sensitivity of the optical signal conversion while reducing the mass-dimensional characteristics of the fiber-optic pressure sensor.