METHOD OF MEASURING THE PROFILE OF THE END OF THE OPTICAL FIBER BY EXCITATION OF AXIAL MODES OF THE WHISPERING GALLERY AND DISTANCE FROM THE EXCITATION POINT TO THE END (VERSIONS) Russian patent published in 2019 - IPC G01M11/02 G02B6/24 

FIELD: physics.

SUBSTANCE: invention relates to the field of measurement and quality control of optical waveguides. Method of measuring the profile of the end of the optical fiber by excitation of axial modes of the whispering gallery and distance from the point of excitation to the end consists in the following. As a source of trial radiation, in contact with the measured end of the optical fiber, a waist of the elongated optical fiber is brought. Through this drawn fiber radiation is supplied with tunable wavelength from an external source, for example, a semiconductor or fiber laser, which through damped oscillations is transmitted to the investigated optical waveguide and excites therein AMWG. Output optical signal is picked up by means of the same drawn fiber or in reflection (on the same side where exciting radiation is supplied), or in transmission (on the opposite side). Spectral response thus obtained depends strongly on the reflection conditions of the excited AMWG from the end of the analysed optical fiber, wherein the number, intensity and lengths of the resonance waves depend on the optical fiber chip angle and the shape of the end face. These relationships are determined beforehand, or by means of experimental measurements of test fibers with different cleavage angle and / or different shape of end face, or by numerical simulation. Another version of measuring the profile of the end of the optical fiber and the distance from the excitation point AMWG to end face is based on pulsed excitation of whispering gallery optics with axial component (AMWG) and using time reflectometer techniques to determine the distance from the excitation point to the end of the analysed optical fiber and to analyse the shape and intensity of the pulse signal reflected by the end of the waveguide and received by the photodetector to estimate the angle and shape of that end face.

EFFECT: technical result consists in high-precision measurement of the profile of the end of the optical fiber and, along with evaluation of the profile of the end of the optical fiber, in measurement of short lengths of a piece of fiber from the point of excitation to its end.

4 cl, 5 dwg