▎ 摘　　要

NOVELTY - An optical fiber comprises glass substrate, buffer layer and waterproof coating. The glass substrate comprises core layer with a diameter of 6-12 μm, inner cladding layer with a diameter of 13-24 μm and outer cladding layer with a diameter of 26-40 μm. USE - Fiber for high-transmission optical cable. ADVANTAGE - The high-transmission optical fiber has excellent anti-heat expansion and cold shrinkage performance, and waterproof effect. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of optical fiber, which involves (s1) fixing pretreated glass substrate by using a clamp, rotating at 2-5 rpm, spinning graphene oxide solution to a pretreated glass substrate at a rate of 0.2-0.4 mL/minute until the thickness is 14-24 μm, soaking in coagulating bath with the mass 2-5 times that of pretreated glass substrate for 46-60 minutes, washing with absolute ethanol and deionized water for 5-8 times, drying for 4-6 hours to obtain graphene oxide fiber glass substrate, (s2) placing graphene oxide fiber glass in a container, introducing formaldehyde mixed gas at a rate of 20-30 mL/minute until the pressure is 8-12 MPa, heating at 80-90 ℃, reacting for 60-76 minutes, heating at 260-300 ℃, reacting for 1-3 hours, washing for 3-5 times with absolute ethanol and washing with deionized water for 5-10 minutes to obtain foam layer glass, spraying heat storage finishing liquid with the mass of 0.08-0.2 times that of the foam layer glass, drying at 60-80 ℃ for 4-6 hours to obtain heat storage foam layer glass substrate, (s3) performing pulse laser deposition on heat storage foam layer glass for 3-6 minutes by taking gallium nitride as a powder target, placing the heat storage foam layer glass in glow discharge equipment, discharging at 500-630 V for 60-80 seconds, etching at the same voltage for 90-110 seconds in a mixed atmosphere of chlorine and nitrogen, washing for 2-5 minutes using 5%mass sodium hydroxide solution at 80-100 ℃, and annealing at 900-950 ℃ for 30-50 seconds in nitrogen atmosphere to obtain buffer layer glass substrate, (s4) dehydrating polyether glycol at 100-120 ℃ and vacuum degree of 0.05-0.09 MPa for 60-80 minutes, cooling at 70-80 ℃, adding acetone with the mass of 3-6 times that of polyether glycol and o-tolylene diisocyanate with the mass of 0.3-0.6 time that of polyether glycol, reacting for 2-4 hours, adding 3-allyl-2, 4-dihydroxy methyl benzoate with the mass of 0.2-0.4 times that of polyether glycol, reacting for 62-74 minutes, adding 4,4,5,5, 5-pentafluoropentane-2-ol with the mass of 0.3-0.5 times that of polyether glycol, reacting for 3-6 hour to obtain prepolymer, cooling at 36-50 ℃, adding triethylamine with the mass of 0.6-1.4 times of that of prepolymer and deionized water with the mass of 0.8-2.0 times of that of prepolymer, emulsifying at 10000-15000 rpm for 20-30 minutes, and heating at 55-64 ℃ and vacuum degree of 0.01-0.04 MPa for 1-3 hours to obtain modified polyurethane, and (s5) mixing modified polyurethane, xylene, cyclohexanone, ethyl acetate, isocyanate curing agent and polyoxypropylene ethylene oxide glycerol ether to the mass ratio of 1:0.2:0.1:0.06:0.06:0.03-1:0.4:0.2:0.1:0.1:0.05 to obtain modified polyurethane coating, spraying modified polyurethane coating with the mass of 0.08-0.2 times of that of buffer layer glass substrate, and drying for 6-10 hours.