Chip‐Based Amplified Spontaneous Emission Source on Er ³⁺ ‐Doped Thin Film Lithium Niobate

Abstract An on‐chip amplified spontaneous emission (ASE) source from an optical waveguide fabricated on Er 3 ⁺‐doped thin‐film lithium niobate (Er: TFLN), is presented. The integrated device achieves a broadband output power of 9.16 mW spanning the C+L band, corresponding to a slope efficiency of 4.7% relative to the absorbed pump power. The device features low propagation loss, large mode field, and single‐mode propagation enabled by the photolithography assisted chemo‐mechanic etch technique.