Fully stabilized 750-MHz Yb: fiber frequency comb: erratum

A statement error was produced in the text introducing the previous literatures in [Opt. Express25, 11910 (2017)10.1364/OE.25.011910]. Here, we correct this error and clarify that this is only due to the simple editing mistake, not related to the scientific misunderstanding about the referenced literatures. Thus, all the conclusions written in [Opt. Express25, 11910 (2017)10.1364/OE.25.011910] remain unchanged by this correction.