BEND-INSENSITIVE SINGLE-MODE OPTICAL FIBRE Russian patent published in 2013 - IPC G02B6/28 

FIELD: physics.

SUBSTANCE: single-mode optical fibre includes, from the centre to the periphery, a central core, an intermediate cladding, a cladding with depressed channels and an outer optical cladding. The central core has a radius r₁ and a positive refractive index difference Δn₁ with the optical cladding. The intermediate cladding has a radius r₂ and a positive refractive index difference Δn₂<Δn₁ with the optical cladding. The cladding with depressed channels has a radius r₃ and a negative refractive index difference Δn₃ with the optical cladding. The optical fibre has a mode field diameter (MFD) between 8.6 mcm and 9.5 mcm at wavelength of 1310 nm, and at wavelength of 1550 nm, the bire has bending losses less than 0.25×10^-3 dB/turn for a radius of curvature of 15 mm. The fibre length needed for attenuation of the LP11 mode to each 19.3 dB at wavelength of 1260 nm is less than 90 m.

EFFECT: fibre can be used in difficult operating conditions, for example miniature optical boxes.

15 cl, 2 dwg