Abstract: The present invention provides a type of steel and a coupler made from same, comprising the following compositions in percentages by weight: carbon: 0.24-0.32%, silicon: 0.20-0.50%, manganese: 1.30-1.70%, phosphorus: less than or equal to 0.02%, sulphur: less than or equal to 0.02%, copper: less than or equal to 0.30%, chromium: 0.50-0.80%, nickel: 0.40-0.70%, molybdenum: 0.25-0.45%, aluminium: 0.02-0.08%, and the remainders are iron and other inevitable elements. The steel of the present invention is advantaged in high strength and excellent toughness and therefore the mechanical property thereof is better than the standard of conventional grade E steel.

Abstract: The present invention relates to a method for splicing a conventional single mode fiber and a photonic crystal fiber having a small core. The method, relying upon an offset fusion splicer, applies repeated arc discharges having weak current and short duration. The method results in a low loss between 1.5 dB to less than 0.5 dB.