METHOD OF RECORDING A BRAHGG GRADING WITH LASER RADIATION IN A BIREFRINGENT OPTICAL FIBER Russian patent published in 2018 - IPC G02B6/34 

FIELD: fiber optic technology.

SUBSTANCE: invention relates to the fiber-optic technologies, in particular to the process of forming fiber Bragg gratings (FBGs) in the light-conducting part of birefringent optical fibers (OFs). In a method for recording a Bragg grating with laser radiation in a birefringent optical fiber, comprising irradiating of a fiber with a remote protective coating with two laser beams, forming an interference pattern, the fiber is preliminarily irradiated with a beam of a coherent radiation source, its width exceeds the diameter of the fiber and directed perpendicular to the axis of the optical fiber. Then the received interference pattern of radiation scattering is recorded and when processing its image, its parameters are obtained: the angular coordinates of the maxima and their intensity and compare them with similar parameters of the interference patterns of radiation scattering obtained by preliminary testing of a similar optical fiber at various known positions of its birefringence axes, and as a result of the above comparison of the parameters, the position of the axes of the birefringent fiber for recording is determined and, rotating it around its axis, to obtain the specified parameters of the Bragg grating, orient the plane containing the axis of the optical fiber and its slow axis of birefringence relative to the plane of incidence of the recording radiation containing the axis of the optical fiber.

EFFECT: increasing the stability of FBG recording by pre-positioning of the birefringent axes of the optical fiber relative to the plane of incidence of the interfering waves.

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