A device for attaching at least one optical fiber to a chip includes at least one nanowaveguide disposed on a substrate of a chip to be attached to an at least one off-chip fiber respectively. At least one oxide taper mode converter is disposed around a nanowaveguide end and in optical communication with and modally coupled to each of the at least one nanowaveguide respectively, and adapted such that each corresponding fiber of at least one off-chip fiber corresponds to a cleaved fiber end each cleaved fiber end to be fused to each oxide taper mode converter respectively to optically couple and mode match each cleaved fiber end to each of the nanowaveguide ends of each of the at least one nanowaveguide via the oxide taper mode converter by a modal coupling. A method for attaching at least one optical fiber to a chip is also described.