Through coating Anti-reflection coating on the end of fiber head and the surface of self-focusing lens, spherical lens or non-spherical lens of pipe cap, the reflectivity is reduced, the transmittance is improved and the signal-to-noise ratio is reduced. Our coated film has the advantages of low reflectivity, high transmittance, low signal-to-noise ratio, small insertion loss, small absorption, good degree of finish, solid film layer, etc., ensuring the normal operation of instruments and communication equipment without interference, etc.