An Erbium‐Doped Waveguide Amplifier on Thin Film Lithium Niobate with an Output Power Exceeding 100 mW

Abstract A high‐power thin film lithium niobate (TFLN) erbium‐doped waveguide amplifier (EDWA) is demonstrated with a maximum on‐chip output power of 113 mW and a gain of 16 dB. The on‐chip integrated EDWA is composed of large mode area (LMA) waveguide structures with a total length of 7 cm and a footprint of 1 × 1 cm 2 . Segmented LMA waveguides are connected with waveguide tapers to achieve on‐chip mode conversion, which maintains single‐mode propagation all over the EDWA even at the waveguide bends. The design leads to a significant increase in the amplified signal power by orders of magnitude and will open an avenue for applications such as on‐chip high‐power lasers and amplifier systems.