Abstract: A new radiation curable Secondary Coating for optical fibers is described and claimed wherein said composition comprises a Secondary Coating Oligomer Blend, which is mixed with a first diluent monomer; a second diluent monomer; optionally, a third diluent monomer; an antioxidant; a first photoinitiator; a second photoinitiator; and optionally a slip additive or a blend of slip additives; wherein said Secondary Coating Oligomer Blend comprises: ?) an Omega Oligomer; and ?) an Upsilon Oligomer; wherein said Omega Oligomer is synthesized by the reaction of ?1) a hydroxyl-containing (meth)acrylate; ?2) an isocyanate; ?3) a polyether polyol; and ?4) tripropylene glycol; in the presence of ?5) a polymerization inhibitor; and ?6) a catalyst; to yield the Omega Oligomer; wherein said catalyst is selected from the group consisting of dibutyl tin dilaurate; metal carboxylates, including, but not limited to: organobismuth catalysts such as bismuth neodecanoate; zinc neodecanoate; zirconium neodecanoate; zinc 2-ethylh