... loss All-optical structure 1x2 optical coupler SM, single window 1310 or 1550 + / -20nm Standard-NC (tube) Tree structure Stainless steel tube ... , single window, standard-NC (tube), 9/125um, tree structure, 1310 or 1550±20nm, stainless steel sleeve (Φ3*54mm), Φ0.25mm bare fiber ...