METHOD OF PRODUCING PAIRED PHOTOINDUCED REFRACTIVE INDEX GRATINGS USING ONE PHASE MASK Russian patent published in 2025 - IPC G02B5/18 G02B6/28 

FIELD: optics.

SUBSTANCE: invention relates to fibre-optic engineering and relates to a method of producing paired photoinduced refractive index gratings using a single phase mask. Method consists in the fact that part of the optical fibre is cleaned, placed in a holder and fixed on both sides by magnets on its protective shell. Cleaned part of the optical fibre is placed in the hole of the holder, a phase mask is placed over the cleaned part, a fibre Bragg grating (FBG) is recorded, the phase mask is placed on the guides of the holder over the cleaned part of the optical fibre and a series of test records of the FBG are made, by changing the height of the guides and determining the resonant wavelength with a low refraction index, which corresponds to the resonant wavelength with a high refraction index, which is formed by a phase mask without guides, and the FBG is recorded.

EFFECT: enabling recording of paired Bragg gratings using one phase mask and providing repeatability of the method.

1 cl, 2 dwg