METHOD OF PRODUCING PRIMARY PREFORM FOR OPTICAL FIBRES, PRIMARY PREFORM, FINAL PREFORM, OPTICAL FIBRE Russian patent published in 2017 - IPC C03B37/18 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of optical glass fiber primary preform. Method of primary blank producing consists in using internal plasma-chemical deposition from vapor phase, wherein doped or non-doped glass-forming precursors are supplied to hollow glass base tube inner side, reaction zone in form of plasma is moved back and forth along said hollow glass base tube length between turning point near supply side and turning point near outlet side of hollow base tube, wherein base tube is installed in furnace and such conditions are created in said reaction zone, that one or more of glass layers packets composed of at least two separate glass layers are deposited on said base tube inner side.

EFFECT: technical result consists in preparing primary workpieces having large used length, effect on optical narrowing can be made independently from geometric contraction, refraction index and/or cross section area can be accurately set depending on primary blank position in longitudinal direction.

17 cl, 12 dwg